They might technically still have them but they would not be able to use them for anything.
Once you leave a position your clearance should be terminated or deactivated.
https://www.youtube.com/watch?v=xHh23OZkDWs
Why do Hillary Clinton, staffers still have security clearance?
Jun 21, 2017
Fox Business
start at 4:15
One can look at it this way:
Security clearance is ‘administrative’.
Access/Need-to-know is ‘operational’.
Having a security clearance means one is part of a pool that can be chosen to be operational.
Obama, Jarret, etc. may be in the pool but may not be chosen as part of an operation.
The problem early on that the Trump camp had were operational persons leaking to the pool and the press, especially after Obama/Lynch pulled off that crazy order allowing 17+ agencies to have access to intel.That was an obvious ploy to allow spying on the Trump camp.