Well, 10 or 15 years sounds good to me. When the Budd consists go, especially the domes, I'll stop riding it if I am still around.
Good luck on getting priority. Legally VIA is in a much worse position than Amtrak. There is federal law requiring Amtrak be given Amtrak both access and priority. While enforcement mechanisms have been lacking (hopefully the new FRA/STB authority on timekeeping standards will improve that), Amtrak ultimately had that in it's back pocket and has very occasionally used it (sued UP a few years ago and UP straightened up somewhat).
VIA has nothing of the sort. Its very existence is based on the Canadian equivalent of an executive order (the actual term escapes me. Order in Council?) the Prime Minister could disband the whole thing tomorrow if he took a mind. It has nothing like the statutory framework that Amtrak enjoys.
PS, my understanding is the situation in Halifax is worse than just being "denied access" to the loop track. That could be worked out as long as the track exists. IIRC, the loop track is being physically torn out as part of a container terminal expansion.