I was looking at the modified column for the SYSTEM file instead of SLUS file. I've got it all figured out now, here are the right EXE dates...
PS2:
Marvel vs. Capcom 2 (U) [SLUS-20486]:
2002-09-12
Viewtiful Joe 2 (U) [SLUS-20939]:
2004-11-12
Yourself!Fitness (U) [SLUS-21149]:
2004-12-21
SSX on Tour (Demo) (U) [SLUS-29161].iso:
2005-07-06