I was never informed of an age limit. It's not really a problem for me, since I bought the domain dirt cheap. Do you have a source for the 10 year limit?
Sorry I actually think I got thrown off by some poor wording in a NameSilo email. After searching I think the actual restriction is that the domain can't last for more than 10 years after the last time you paid (but you're free to keep moving your 10-year window by continuing to pay) which is way more like what you'd expect. My bad if I alarmed you! I was super confused myself and I was wondering why that supposed limit wasn't more well known lol.