Don't see how the BC government can force CP or CN to maintain their network, besides, their private businesses and the Fraser Canyon is vital to their operations I don't think for a minute that either of them are neglecting their obligations in that regard.
It's also a joint operation as CP and CN share trackage rights from the Mission bridge nearly all the way to Kamloops, instead of having trains meet at passing sidings on their own routes, all trains running east take CP trackage and all trains west take CN, it's extremely efficient and it also provides redundancy, Canadian Pacific was up and running again only a week after the major floods.