It also isn’t a behavior change 
JPA Criteria API is simply a different API with different semantics. There is no expectation like “empty disjunction behaves the same way” and also, the behavior never did change. The JPA Criteria API implementation always was this way.
I understand that you might have been caught by surprise by one API behaving slightly differently than the other since both APIs use the same name/concept, but that’s just how it is. Good that you have a “workaround”, though really it is rather an implementation of your required semantics, so it can hardly be a workaround 