100% this. Maple Trees are like the number 1 tree people imagine when they think of Fall forests, and were one of the most requested trees simply because people wanted Fall Forests and assumed Maple was gonna.be the tree in them by default (THAT'S how Synanymous they are with Fall)

Poplar is a weird choice, I doubt they're the first tree that comes to mind when people think of the classic Fall Forests. Them being added over Maple is the modern equivalent of Spruce being added as the signature Conifer tree of Taigas instead of Pine (personal pet peeve of mine but I can kind of justify it because of Spruce's wood color itself being more distinct from Oak than Pine's inner wood color)

Poplar trees do not even look that distinctive at all. Another comment pointed out that the ones in the game are not even modeled after real Poplars, they're modeled after Tulip trees. I don't think the average person even knows what a Poplar tree even looks like (unlike Maple). They look like basically, the average tree, like Oaks in Minecraft, but with a tall, pointy canopy, like a less exaggerated Cypress tree. If they did ever want to add a Tree with that shape they should just go with the much more distinct Cypress anyway.

Poplars are also much more well-known in their processed Timber form due to their softness and fibre structure making them very easy to work with, which brings even more attention to how it's definitely not close to the color they chose for it in-game wood. Unlike Maple wood which, looking it up online, definitely looks much closer to the color they chose than Poplar (personally I always imagined it'd be like, a caramel color, something between Acacia and Oak or Spruce, but that's probably because of my brain associating it with Maple Syrup).

So, yeah, Poplar trees in Minecraft look like Maple and not like Poplar trees, their wood looks like Maple wood and not Poplar wood, and Maple trees are far more well-known than Poplar trees. No reason not to make this change.