I get the feeling that Ten Hag told him that he won't have a key role and he won't build around him, so now Ronaldo is desperate to leave. Framing it as if he wants to play CL is better for his image than no longer being a key player or him doing poorly for a side not in the CL.
Ronaldo's summer departure was always in question once United crashed out of CL and couldn't get 4th place to secure CL for this season. It was a reason why he came back, plus to block City from getting him (even if that was a ploy to force United's hand more than City actually signing him).
And it's not really his image he's trying to protect, just more like he wants to be at the very top. And similar to the Chicharito video I posted yesterday, he's coming to the realization in his own terms that he's being phased out at the very top of the game because his talent is dwindling as is his overall impact to a seriously competiting side. It's just the reality for all top level athletes and this is his story, his realization.
Ronaldo has to suit the team and EtH, rather than Ronaldo being the focal point. A fully fit Martial is a more impactful player now, than current Ronaldo. Both have their issues, but learning how to play with a Martial type player with his skillset is much more beneficial going forward than trying to shoehorn Ronaldo.
Could careless what happens to Ronaldo this year or next. He was a lame duck after last season and here we are. I would like for him to stay and do what EtH asks of him, but it's up to the player to accept those terms and embrace it. The club is bigger than Ronaldo and whatever his end game is now at United, not bothered. Team will continue to evolve without him as we've seen for the past month or so.