requested to be suspended
This still sounds weird to me.
due to not feeling they are doing their best as idols, and for such reason not deserving being part of the group in such situation.
In that case they should've done like Shihori and quit. This sounds like a half-assed 'solution' to me.
They feel they aren't doing their best, so they want to be suspended? No! Don't leave and start doing your best! What good is a temporary suspension gonna do?