If you're going to put the slides of your presentation online but then say they may be updated, for the love of god, please update it. There is no point in students grabbing it if it's different to what they see in the lecture.
Sure it's better than nothing and you can make changes yourself, but who has the time to do that? I'm juggling other lectures besides yours.
You've got the most up-to-date slides, just upload them.