Sakamichi Trainees/Kenkyuusei are reportedly didn't want to join Keyakizaka46. According to Daily News Online, a new group with members of Sakamichi Kenkyuusei in it may be launched with probably new concept.
Several names like "Hinokizaka46", "Kagurazaka46", and "Kasumizaka46" have been proposed.
They were each scheduled to be assigned to a group but many rejected to be Keyakizaka46 member. Sakamichi Kenkyuusei members was recruited through "Sakamichi Joint Audition" back in 2018. It is unclear why these trainees don't wanna be grouped with Keyakizaka46.