To the OP, I suspect your answer is actually something like option 3: Your husband is still employed but per diem employees are not benefits eligible and/or he didn't work enough hours to qualify for this particular benefit. I don't think it's as black and white as you're seeing it.
I have never heard of employer "having" to reimburse employees for licensing costs. An employer that does so is offering this benefit as a courtesy and employers
can change these benefits pretty much whenever they want. I have never been reimbursed for any licensing fees.
WifeMotherRN1, no that isn't a HIPAA violation and I don't think it's worth pursuing. The MD was aware of this information because he was your colleague not because he was your doctor and he has no legal obligation to keep this information private. When I worked in the hospital, word of stuff like that spread very quickly. If you don't want people to know, don't tell anyone. Also, it is a good idea to create a new thread if you have a question separate from the ongoing discussion so as not to hijack the thread. If you pursue anything, I would approach the MD and say "in the future, I would appreciate it if you wouldn't share personal information about me with patients, I like to keep those relationships strictly professional."