You can evaluate whether you have asbestos fiber in the roof tile by taking a small sample to a laboratory that does asbestos testing. I will generally cost less than $40 to find out. See if you can find a fragment already separated for the analysis.
If it is asbestos containing, it is not the end of the world, but you will need to take some extra precautions in handling the material during maintenance or removal.
I don't know why your roof should be replaced soon. Are the tiles cracked? Are you aware of damage to the roof deck? Even if some membrane or felt needs replaced, the roof can be lifted and replaced in many cases.