First of all game balance doesn’t need to change this much (or even at all) to stay fresh or keep a community. There is almost always a remaining community that stays with an online Blizzard game, and new/updated user-created maps or mods practically ensure that there is fresh content on a regular basis. Starcraft Remastered game balance was not changed this much, or at all in fact. I doubt Diablo 2 Remastered will have balance changes this drastic either if any, and that’s despite them wanting to keep the original Diablo 2 playable. Looks like they aren’t planning any at the moment: xhttps://gamerant.com/diablo-2-resurrected-no-planned-balance-changes/ World of Warcraft Classic didn’t get balance changes either (or not much at least), and look how popular that was despite it not even being a new game. Guess the one game out of all these that got the worst reception by a long shot so far? Warcraft 3 Reforged.
Second, you can do balance changes without the core changes they’re doing. Unit/upgrade/spell/item stats such as health, damage, cost and cooldown can be tweaked to address balance, without changing more core aspects of the game like the main features of an ability, what abilities a unit or item has, number of upgrades and tech tree requirements. I mentioned the 11 food provided by a Great Hall change because, despite just being a supply value change, it’s completely unorthodox. Every race’s town hall had always given 10 food, orc included. That was a defining aspect of Warcraft 3. But then some new developers takeover and decided they want it to give 11 food, and while leaving the others at 10 food.
Third, it might be different if Blizzard still supported the original Warcraft 3 with battle.net, before all the Reforged balanced changes (including any after version 1.26 when the Classic Team took over). But they don’t, and they actually auto-updated most people with a recent version of the game to Reforged. You can’t even play RoC ladder anymore either (or custom games with the RoC ruleset unless all the rules are changed to match it). Reforged’s battle.net and melee games are all under the TFT ruleset.