If the final rule is that kids can freely transfer after a coach leaves, when they are a grad transfer, or if the school is banned for the post season, I think that is fine and it shouldn't hurt UConn. That said, you could paint a scenario that a coach leaving could decimate a roster. Imagine if 40 kids transferred from a football team. The school would not be able to field a team the next year.
As for P5 vs G5 impact, I think the impact could be just as bad for P5 schools as for G5 schools. Why? In football, so many kids are buried on P5 depth charts that they would probably consider transferring if they were a free agent. In basketball, the same is true. Look at a kid like Semi Ojeleye at SMU last year. Top recruit and was buried on the bench at Duke, so he transferred to SMU, but he had to sit out a year. Ended up as AAC player of the year.
In basketball, UConn pays at the high end of college basketball, so if we are successful, coaches leaving voluntarily is probably not a concern.