I emailed Pega certification about this and was told they don't know when UI Specialist 7.2 is coming out. I'm hoping some other Pega staff on here may have some idea. I'm a new SSA and have done all my certs in 7.2 and hoping to do UI Specialist in 7.2 as well. The client I'm working on is also on 7.2.
If UI Specialist 7.2 is coming out in the near future I'll be happy to wait.