Sync for Reddit included them, they were just off by default.

Well, reddit had chat and we weren't allowed to have it because they decided they didn't want to create an AP for 3rd parties to use.

I wouldn't presume Lemmy will lock features to its own app or site in an effort to monetize them or keep their users in their own apps.

I expect that ljdawson will bring in the features of the Lemmy site over to the app as he sees fit. And that we'll have a pretty complete experience.