With all the previous delays on the T-series remaster, I suspect the vehicle team will just be using the extra time to catch up, and start working on stuff for the next update in advance. As for "an unexpected new vehicle or remaster that's not part of the T-series", probably that D55/D65 thing.
Secret snake peak teaser with insider leeks - save this image before it gets censored by devs. Edit: it says "family", is this a fast and furious reference!?