I met one scrum master colleague recently and when we were discussing about scum implementation in his project he pointed out that all ceremonies are not required when your delivery is over and only bug fixing is pending.
According to him, Sprint planning meeting, retrospective, backlog refinement meeting become useless and Only daily standup and review meeting they are conducting in his project and he faced no issues with it. His team could fix all bugs in timely manner without the need of this meeting.