IMO, legacy would still be the first iterations of RoC and TfT but I digress.
Actually, what I might say is that 1.22ish is legacy.
From what I can tell/remember, the 1.23-1.26 patch cycle in 2009-2011 was created to start trying to fix the virus exploit. That was the only reason. The
hashtable natives were added with guidance from Vexorian and maybe a few other community members to resolve what would otherwise have been a glaring flaw / glaring loss in the map script APIs. Because otherwise fixing the virus exploit made return bug not work, which made cheesing Gamecache to be away to have a hashtable structure not work, and so the
hashtable natives were necessary to keep the system running despite the effort involved. There were like 2 other natives added as a friendly nod to Vexorian that weren't strictly necessary like GetSpellTargetX and GetSpellTargetY but essentially they were just trying to "save" the mapmaking in what was otherwise quite literally the custom games apocalypse that made the most customized and most interesting custom maps die -- in what was otherwise a backwards compatible system.
But if we look at the date of Activision buying Blizzard, I think it was slightly before that patch cycle. And if we look at the
hashtable natives in the
TriggerStrings.txt and
TriggerData.txt files in the game, they are
thrown in haphazardly to what was otherwise a harmonious and well organized system.
In other words, if we ignore community and think more about the technology history, I would almost sooner say that the
true legacy version of Warcraft III would/should be the game as it was circa patch 1.22 in 2008. It was at this time that Activision bought out Blizzard and someone, some sneaky person inside of Blizzard, changed the code of Warcraft III so that it no longer looked for
a physical CD rom drive in the computer and would instead be launchable as a standalone Windows application after it was installed. It enabled the future of digital downloads for the game but it was essentially also I think the cutoff point where some very bright person made the true legacy CD game of Warcraft III be only slightly modified in this way so that it was playable without a physical CD drive, while their company was getting bought out probably. I have a copy of that version on my computer which seems to be a 1.22 game install but maybe where as a user I dumped the 1.23 world editor EXE into the install because it likewise can launch without a physical disk in the computer. So then it operates as my oldest possible playable backup which requires no physical CD media.
On my computer I would think of that version as the true
legacy and I am frequently playing Warsmash emulator using that version as the asset source. The Warsmash emulator provides the implementation for hashtable natives and other code changes, so in all reality there's like nothing lost and it's literally the classic legacy game with support for all sorts of maps from future versions. It's well within the realm of possibility to think of this as being a defining legacy version, even if it's not the pop culture world view of looking at 1.26 as being that thing because it was live for 5 good years without changes.