I've been saying this for a long time, but Rouge exists as a cabin crew labour cost management tool only. It is no longer "Air Canada Rouge, a low-cost leisure airline". It is "Air Canada, operated by rouge". The best analogy is "ANA, operated by Air Japan". Same planes, same amenities, same service.
The rouge 7M8s, seating reconfig aside, or no different than before. There's no more rouge livery, the branding is de-emphasised. There's simply a decal near the door that says operated by rouge. Even the safety cards are no longer "Air Canada rouge' branded - they are Air Canada branded with an operated by rouge logo underneath. The uniforms have been the same since the last refresh except a different scarf and nametag. rouge J service and product has been the same as narrowbody mainline J since COVID. which does exceed international PY. And rouge A320s have always had wider seats than mainline 223s. So those grievances filed by the union should have been filed a long time ago.
Any route that has been operated by a mainline 7M8 could be operated by rouge 7M8 tomorrow. Some may not for other logistical or operational reasons, but I wouldn't say "oh A-B would never be operated by rouge" if a 7M8 has operated today. Some routes like YVR-SFO could see a mix of mainline, rouge, and express.
I'm genuinely surprised rouge survived that last FA bargaining round. The cost savings for AC (and this is generalised) for rouge are slightly lower starting wages, not really any significant salary progression into more senior years, and the lack of the service director position (just a FA who takes the lead role for a sector gets a pay premium). This is also to disincentivise FAs from staying at rouge for a 'long' time. Overall creates a more predictable staffing cost for routes operated vs the more diverse seniority mix that can happen at mainline.
This is a calculated gamble by AC, to see how far they can push this. It's by design that transitioning 7M8 to rouge (which they "have" to do for the pilot agreement) is done at the most minimal cost and effort that it could easily be reversed. There absolutely is a 'close down rouge' plan that exists if this doesn't work out. Not much for AC to 'lose' at this point IMO.