Presumably this is the cause (I’m not certain because I haven’t had my British routes on my game for a while), but I’m fairly sure the heritage runs on East Coastway, London Commuter and others used to feature more locos. Currently my only options on PS5 are Classes 45 and 47. I’m sure I was able to select Classes 40, 31, and 37 before. Not a major issue of course but thought it worth mentioning incase anyone is still fixing TSW2.
You are correct. Legends of GW is also missing 45s and 47s so there are definitely issues with some DLC not being tied up. I would log it on technical if I were you