Should be perfectly fine to use. Like anything else I think the biggest factor is where they are stored. In a cool dry place they should be fine, but if stored outside in a damp barn or shed rust might start to form.
This is how I feel as well.
I have a few filters from 2013 that are in my stash, and are stored inside in a closet with minimal temp and humidity fluctuations.
At 10 years I may start to worry if they are cellulose media, but blended or synthetic media, I would not worry.
I know 53' Stude cut open some 20+ yr old Fram Tough Guard filters and they appear fine (LINK