The problem with rebuilding cars is that it still leaves you with what at the core is still old equipment. Nothing lasts forever, not even steel centre sills. Even before this funding announcement VIA had revealed they plan to soon retire the ex-Amtrak stainless steel coaches.
The LRC coaches have been the backbone of VIA's corridor fleet since they were built in the early 1980s, which will make them nearly 40 years old by the time their replacements arrive. While they are not nearly as old as the Amfleet (and nowhere near the Heritage stainless steel cars) they are significantly older than the Acela coaches (which are based on the LRC design) which Amtrak will be retiring around the same time. Perhaps the Bombardier LRC family simply does not age well (they don't build 'em like they used to?).
The Renaissance cars were a maintenance nightmare (frozen plumbing, not handicap accessible) when first acquired, and they still have ongoing issues. Their availability rating is far lower than anything else VIA has, especially during the winter.
VIA has not stated that tilting will be a requirement of the new cars, but a properly working system (unlike the LRC) would be quite helpful.
Meanwhile the long-distance ex-CP stainless steel fleet rolls on, albeit fewer miles at slower speeds than the corridor fleet.