I won't be buying it on release, if it has 1UPT. Will wait a year or two and pick it up on sale. If it goes a sensible route and has a compromise - say 4 units per tile, would definitely be interested in getting it on release. I am one of those old crusties whose played since Civ 1 and though I don't hate 1UPT, I don't like what it does to the game. Perhaps if we call them "armies" instead of loaded terms like "doomstacks"? The problem I have is that 1UPT slows the game down. Causes blockages as you move just 4 or 5 units. And I dont think this qualifies as an "interesting decision"! Its busy work. And completely wrecks the scale. Civ has always been abstract, which is fine. But only have 1 unit of archers, say, in a tile which must be several miles across, is kind of absurd. And when they start firing over hills...
Games like Age of Wonders are fine with a limit (6 units per tile, I think). This works so much better than both unlimited doomstacks and 1UPT. What would need adding is determining the battle outcome, based on the composition of those stacks. And that, I guess, is the challenge (not the tedious 1v1 string of unit battles in older Civs) . Especially at the abstract distance and time scale.
It's good to see that many are not specifically attached to 1UPT, at least. I always had the idea that if they changed it, they would lose most of the newcomers to the series since Civ 5.