Risk:
If you build up a Frankenstein bike with ancient parts (like 2018 era fork damper) or wildly mismatched parts it will have very little resale value as a complete bike if you don’t jive with the bike. Buyers won’t know how to price against OE build spec unless you strip it back to the frame.
So if you have parts that you want to use, great. But if you are gonna go out and buy parts, seems like the right move is to buy parts of the same general vintage as the frame.