14.0.0 via #3295 introduced this bug.
#3295 introduced a behaviour where bulk updates clear the persistence context. Now the lazy loading of a BeanCollection works with an assumption that the "parent bean" is in the persistence context (and this assumption is broken with that change for this test case). That is, the bulk update is clearing the persistence context - removing the parent bean BEFORE the lazy loading is invoked ... and that doesn't then work because the parent bean isn't in the persistence context.
This fix means that when lazy loading many's, the parent beans are putIfAbsent into the persistence context.
Rob Bygrave