Should I share course notes from my previous university with my students?
If these were my notes, and you asked if you could share them with your students you would get permission in a heartbeat. In fact, if I had continued teaching the course, and thus continued to develop them, I would probably sent you the most up to date version of those notes. I am not alone in that, I remember that several associations have been trying to set up a repository of such teaching notes, which struck me as a good idea, but I don't know what came of that. However, I have come across people who take a more restrictive view on their notes. 

So, I think the best thing you can do is ask. Best case is you get the most up to date notes and a potential reference writer gets reminded of you in a positive way. Worst case (s)he says "thank you for asking, but I don't want you to release those notes". If you don't ask, release the notes, and (s)he finds out, things could get a lot more ugly.