If you look at the last gasps of the original line, with Star Brigade and other sci-fi additions, you can go fairly futuristic with it and have it still be GI Joe. While as a kid, the grounded nature of it (characters who looked like actual soldiers, vehicles that either looked like real military vehicles or like they could have been real military vehicles) was part of what defined GI Joe, it wasn't the main thing. I think to see how far you could go with the futurism/fantasy, you have to look at the competitors and its failed successors.
You could get that same thing from Sgt. Rock or the myriad knock-offs. The Corps! and Remco's various offerings may not have had the vehicles, but they had the "could be a real soldier" look to them, yet they didn't click. However, The Corps! is still around in some capacity and was the only non-Joe line with any staying power. Was it because they were the closest in appearance to looking like real Joe figures? Maybe. But I think there's more to it.
With a more Joe-like construction and stronger media (sure, there was a Sgt. Rock comic, but no pack-ins, cartoons, commercials, etc.), Sgt. Rock may have been a contender, but it was too weak and Remco quickly gave it up for the more direct Joe type knock-offs. Lanard had a much better go at it, and it's because they made interesting looking characters with interesting names. You had characters like Junkyard, Flashfire, Avalanche, John Eagle, Whipsaw... all powerful sounding names. They also had some basic bios on their cards, similar to the GI Joe file cards or TF tech specs. What they didn't have was an enemy. Every The Corps! figure was made to be a hero - even the Dreadnok looking characters like Whispering Willie and Crowbar. A hero is only as good as his villain, so The Corps! was only good for filler in the Joe ranks. Of the non-Joe toy lines that were out there, the most Joe-like I can really think of was: Exo-Squad - a futuristic military toy line with lots of articulation on the figures, extensive bios on the packaging, comics, a cartoon, and compelling villains.
Contrast Exo-Squad with the toy line that
should have been a more futuristic GI Joe: GI Joe Extreme. Extreme was an extreme disappointment. The toys had no articulation and were quite hideous, embodying everything that was wrong with the '90's. The characters were flat and one dimensional, even for cartoons/toys.
Compare Iron Klaw:
Quote:
The mastermind and leader of the SKAR forces... completely power-hungry and bad to the bone...poses as Count von Rani while secretly plotting military operations and evil invasions in his ultimate plan to rule the world.
To Cobra Commander:
Quote:
Absolute power! Total control of the world...its people, wealth, and resources---that's the objective of COBRA Commander. This fanatical leader rules with an iron fist. He demands total loyalty and allegiance. His main battle plan, for world control, relies on revolution and chaos. He personally led uprisings in the Middle East,Southeast Asia and other trouble spots. Responsible for kidnapping scientists, businessmen, and military leaders, then forcing them to reveal their top secrets.
"COBRA Commander is hatred and evil personified. Corrupt. A man without scruples. Probably the most dangerous man alive!"
or Phaeton:
Quote:
Most cunning and lethal Neosapien ever created. Started as spokesman for Neosapien population on Mars then quickly rose to become first Neosapien Governor General of Mars planet. United all Neosapiens to fulfill their destiny to rule the Universe. Masterminded and led the suprise Neosapien attack and takeover of the Homeworlds. As the ruthless dictator over all mankind, his Exo-Technologically advanced mobile command E-Frame allows for direct communication with all Neosapien battle forces. Ability to fire his missiles and rockets with deadly accuracy whether flying at hyperspeeds or waging war on land makes him the ultimate warrior. Knows that to defeat ExoSquad is to defeat the human race.
To me, Phaeton comes across as more the spiritual successor to Cobra Commander than Iron Klaw does. All we learn about Iron Klaw is that he's "power hungry" and "bad to the bone". We're told that Cobra Commander and Phaeton did things, that they are things. They seem like real threats. Iron Klaw comes across as the villain of the week on some failed '90's cartoon who was forgotten about before the next episode. While less futuristic and even having the "GI Joe" in its name, GI Joe Extreme feels less like GI Joe than Exo-Squad does. Had Hasbro released Exo-Squad instead of Playmates, it could have easily been sold as essentially "GI Joe 2099". Even giving Cobra Commander cameos in Extreme never made it feel like it was GI Joe.
Then we have GI Joe: Spy Troops, GI Joe: Valor vs Venom, and GI Joe: Sigma 6. Each had their varying levels of futurism and sci-fi elements added. They also leaned heavily on using existing characters and names, with few, if any, new characters added. Overall, Spy Troops and VvsV did okay. Sigma 6 had a poor showing, but it was more because of the figure aesthetic and scale, not the futurism of the premise. In fact, fans seemed to like the designs for S6, just not the execution, especially having two scales - one with small, limited articulation figures and great vehicles, and the other with larger, well articulated figures but highly stylized.
That's a lot of words to say that what made GI Joe actually be GI Joe was the fleshed out characters (heroes and villains), media support, and a well thought out toy line with aesthetics and articulation, and in a consistent scale. All that said, I think having a GI Joe set in 3023 could work and be accepted as GI Joe, as long as it had the same 'feel' as RAH - well-developed characters with individual personalities, realistic designs, a strong central villain with their own army, media that carries the premise well, and toys that are well articulated, aesthetically pleasing, and supplemented with realistic looking equipment and vehicles.
Now, if you're talking OG GI-Joe (the 12"ers) all bets are off and I don't think those guys would be happy if GI Joe advanced beyond 1970's tech.