A loco pack for the upcoming west cornwall route could really offer some more player variety. I reckon the best locos to include would be the class 43 HST in Intercity Swallow livery. The Class 47 in Intercity Swallow livery with MK2s also in the Intercity livery. Possibly as well the class 37 in the Intercity livery for the more local services. This would add loads more services into the route and make it much more enjoyable.
The 37/5 has already been announced to be part of the route along side the 150/2.. "West Cornwall Local is releasing with the Class 150/2, the Class 37/5 and two wagons. The wagons are the Turbot and the Seacow. Both locos will offer a lot of options for driving the Penzance route. The 150 is an all-new train to Train Sim World 2 and the Class 37/5 has been updated visually for the route plus this version can now be reskinned in the Livery Designer." - https://live.dovetailgames.com/live/train-sim-world/articles/article/on-the-way-to-st-ives
We already knew it was being released with the pack. You're missing the OP's request. The class 37 in Intercity livery along with the other locos (at the OP's request) to be used for passenger services. The current 37 is for freight only...