Seems like via has added an HEP2 set back to the QC-MTL-OTW during the venture reconfiguration changes. I’m currently on train 33 and it is made up of 5 HEP2 cars and double ended engines. They even reversed the train direction in Montreal like with the ventures instead of backing out to the bridge as they used to do with double ended LRCs so this seems to be a new official practice.
Looking at
https://www.traincar.info/ it seems like this is a planned change and that train 31 now uses 4 car ventures, with only one business car removed.
Also mildly interesting, there was a land acknowledgement in the departure announcements.