This wouldn’t work or make sense for cross posts in communities to have discussions specific to that community.
For example I run the !ancientcoincleaning@lemmy.world community. If a post from there is cross-posted in !ancientcoins@lemmy.world their discussions about the coin would be different (focused around numismatic interests as opposed to cleaning focused discussion). It wouldn’t make sense for the comments to be merged.
Lol, this one is great