Granted it is makes no sense in the real world for Heather to be let out of jail.
Soaps have a limited number of core characters and past characters to work with, so they often come up with very strange, unbelievable ways to bring back characters -- such as however, since soaps are pretty it made no sense to bring Ian Buchanan back as Duke ... only for it to be revealed he was really Faison made up to look like Duke.
All I ask is that a soap put some effort it coming up with a way to explain the impossible ... and if the character and storyline is worth it, I can be a good sport.
Given the long history between Laura and Heather, she is the perfect vehicle to make the move to start the process of adding Heather to the show again. Whether it is good or bad will depend on what they do with Heather once she is back on the show.
Karen L.