Episodes marked as aquired in the watchlist seem to disappear forever from the watchlist. This makes the watchlist not be watchlist but a "not-aquired-list", which makes the new feature rather counterproductive in the watchlist.

Shows with a backlog when marking one as aquired in fact increases the watched counter as well (e.g, 3 episodes of a new show have aired, marking the first as aquired results in a display of "1 / 3" below the show name).

Until the watchlist behaves properly, and just keeps displaying aquired episodes in its list, just marked as aquired, this feature is not usable for watchlist users, unless they have a separate means of keeping track of unwatched episodes that are aquired (perhaps via a special folder on their machine, or a streaming service doing it for them), and even then it's then useless for easily marking them watched, as they aren't shown.

I guess alternatively it could be configured what is shown in the watchlist, but only hiding watched and skipped episodes should be the default.