I think it's 50/50 really, I can see them not adding trophy support because like people jave said, who's gonna go and recode games from 20+ years ago when some of those companies don't exist anymore. However, I'm cautiously optimistic and really hoping they do, what with the previous patents for trophy support as well as the new game preservation team.
If they don't have trophy support, I'll be happy if they include games I never played that interests me, like tomba for example. However if they do include trophy support then I'll be screaming for them to add
Legend of legaia
Digimon world ps1 ps2 and psp games
Monster rancher series
And many many others!