I thought that it was unnecessary to update the t series because so many mods used the t series truck AND the trailers. When the update came out all the bogies and wheels broke on most of the mod trailers/ legacy trailers which made them useless.
It was going to get updated eventually - I'm only surprised it didn't happen sooner. There might be some issues I have with the T-Series remaster (mostly the fact that it still has only one engine), but overall, I'm very happy with it. It's great to finally see a cabover semi in the game, along with many other things the remaster added.