As a Galatasaray fan, the three players that are we are considering letting go (or they are considering leaving) are Ziyech, Angelino and Ndombele. The most logical one is ndombele, because he is a good player and definitely playing great when he does, but its been months and he is still not in form, when a player is getting fatter and fatter when he should be getting in more shape to play, you do not really have to wait him to be better. It is %100 logical move to just let him go. Angelino came in with a big fury, played well, but recently we have been using our right attacking winger (who can play striker and did so in national team) Barıs instead of Angelino at left back, consider how worse you need to get that a team would rather use right winger at left back instead of you. The only one that doesn't make sense is Ziyech, he is an amazing player, he did so much, but he also doesn't want to play, he always looked unhappy, we couldn't make him happy, and he notified his agent to find another club. It happens, we just have to accept that, if he wants to leave then we wish him the very best and just look for someone else. To be fair one left back and one midfield without any other addition was our request as fans, if they can do that, rest would be simple enough for us. We already have players in every other position.
January transfer window is here, most teams would use the time to gather up new intensity to their squad, switches would occur and definitely either or positive or negative change in the team's performance would follow suit. The Turkish side have seen an essentiality of a switch up, it may seem advantageous to them although it's all ahead of the final half of the season as well as European cup contests too.
These players have done their best for the team no doubt but there are decisions a team makes for their own selves, although some may not necessarily be favourable to the players but it just has to be made. This is an avenue for the team to make better signings that'd improve the squad strength. They're already a good side judging from their UCL performance and their domestic league's performance too but the management wants better and so it's a welcome if they decide to let go off of some men to bring in new ones. Their decision should be respected and accepted.