I don't know much about this stuff so forgive my ignorance here...
Is it mandatory that at some point they will have to come out?? Or is it only if they're an issue??
Not mandatory, but from what I've been told it is almost inevitable that at some point they will cause complications.
I still have all four and I'm 28. I talked the Army doc out of removing them about a year ago during an active duty training stint. During my last dental visit, and pano X-Ray, my regular dentist noticed one of the lower ones beginning to impinge a nerve (apparently a major facial nerve) and told me I no longer had an option, at least that one had to be removed.
If one is a problem, I may as well have them all removed. The Oral Surgeon told me during the consultation that my upper, impacted ones could cause sinus problems down the road if left in. F¥€£ it, pull 'em...