The presses ran on Marvel Age, but they were more often considered promotional material, not "real" comics, back when they were issued (a lot of them free with Diamond Previews from subscription services), so I think a lot of copies were discarded/destroyed before people finally realized there was collector value to them. Certainly most Darkhawk #1's got a bag and board at some point. The Marvel Age DH preview, not as much.
I just dug this one out in keeping with the "these were ephemera" theme. I was able to pick up a closing LCS' Marvel Age stock about 10 years ago. None of them were bagged. This one made it through OK, but I think I have some more I bought in a unlabeled box and am hoping they're in better shape. Certainly the one I got from my sub service when it was new should be.
I loved Marvel Age, and started to save them from about #20 on so I have a decent collection, although I missed plenty towards the end, which was about 10 years later, with #140
As a kid without a lot of money, they looked like comics, had actual comics sometimes, great covers usually, and were cheap!
I really liked the annuals. They went all-out on those.