I think that barring any long-term issues with the hardtops (delamination, etc.) it's only a matter of time that most people will consider them a big plus when purchasing a used game. There will, of course, always be a premium paid for a restored or reproduction PF but for the "mass market" in pinballs hardtops will be the gold standard.
I also wouldn't at all be surprised if you start seeing a substantial number of new games being produced with hardtop-style playfields right from the factory (DeepRoot?). A better product is a better product.