Since it impacts gameplay in a significant way, it absolutely does mean it belongs in Classic WoW. Even if it’s the clunkiest most awkward thing in the game, if it was in Vanilla circa 2006, it belongs in Classic WoW. That’s literally the justification given by Blizzard for Spell Batching, too. Most of us are looking for an authentic WoW circa 2006, it seems, so we agreed with Blizzard.
[ Quotes from “Spell Batching in Classic” blue post ]
We’ve been working to ensure that in WoW Classic, the gameplay of activating spells and effects will not differ from the experience of playing original WoW.
As with many other areas of WoW Classic, authenticity is our primary concern.
(Hilariously, they even call out your specific example)
Two warriors will be able to Charge one another, and the end result will be both warriors standing stunned in each other’s original location.
We think it’ll be fun to see those sorts of things happening again.
So there ya have it, literally the stated goal and intention is to be authentically classic and re-create these gameplay altering mechanics so that everything from PvP to raids play as close to 2006 as possible.
You’re effectively talking about a handful of variables in the code relating the at what minimum movement speed “Leeway” is in effect, how much further the reach is when “Leeway” is active, and maybe a couple of others. Any adjustments made to “Leeway” between now and release are going to be a matter of tweaking some integer values. It’s not some complex logic.
So the only valid arguments to changing “Leeway” are video or some other actual proof that would result in Blizzard lowering or increasing those integer values. Barring actual proof to the contrary, I am comfortable trusting that Blizzard was able to determine authentic values for “Leeway” as is currently implemented.