Honestly it will make sense to finally see either Guller or Endrick or both going out on loan in the summer to further their development process rather than keeping them weekly kn the bench with little chance to play and improve. Bournemouth will obviously be benefiting more if these swap eventually happen, both players will definitely bring improvement to their team for the length of time they will be part of the club.
Personally, I would only loan Endrick out so he can gain more experience. For me, Arda is a much more complete player, I also don't like the way Ancelotti has been managing the team lately, I think he's very submissive and wants to resolve everything at the last minute, That's something that doesn't work right now, Yes, he's been a bit of a loser, but that's not what we're looking for I would leave Arda.
For me, Endrick doesn't play much. I know he's scored goals, but he's not really as outstanding a player as Guller.