I'm no expert, and you are right he did leave sometime ago, perhaps there were changes with regards to protecting classified information after he left.
Classified information does not become unclassified just because it is publicly available if I remember correctly. Either way, I can't comment on whether including them in his slides is disclosing/divulging or not.
Classified information does not become unclassified just because it is publicly available if I remember correctly. Either way, I can't comment on whether including them in his slides is disclosing/divulging or not.