Honestly it's too hard to guess anymore but Ike and Vox were really close to Selen (and at many times Vox seemed like he already had one foot out of the door). Nobody likes seeing their friend treated so poorly and discarded in this way but it will hit those two particularly hard. Ike and Selen did a lot of duo collabs together (tfw they will never finish Dead Space 3) and
even did a cover together (sort of), and Selen liked Vox enough to carry his ass to masters in OW2 offstream (and also invited him to various collabs with big OW pros/content creators who Vox idolized when he was younger), outside of their fun banter during the NijiCancelled streams and other collabs. They both really respected her as a content creator and as a friend.
Fulgur was also good friends with her but I don't think he would leave just yet. Rosemi was close with Selen but I guess that won't become an issue until her contract is up again next year. From the newer members I imagine that Vivi is really going through it at the moment given that she was a big fan of Pomu and Selen before she joined.