Well, since the original sounds were taken from the actual loco, probably no need. The only thing they might want to update is the rather anemic horn.
those sounds absolutely were not taken from the actual locomotive. Heck the TSC C44-9 (Dash-9) locomotive FROM 2012 had better sounds. That’s over 10 years ago.
I dunno if they're 100% accurate, but they're close enough for me. Yes, the only issue (for me) was the horn was very bad. We have tons of CSX, NS and AMTRAK around here and the thing TSW gets wrong is the horns on them....