Tend to side with Bale, even on the part of not wanting to travel. Given the recent trends, he was very unlikely to be on the pitch, even for a time-wasting or even game-saving cameo. Zidane probably even said as much face to face & asked whether he wants to go on the trip or stay home, maybe even hoping Bale stayed home so he can get another player some time. In such a situation (& the current pandemic), why should Bale even go through the motions for the CL trip to Man City? If it weren't for COVID, I might side with RM, but why even expose himself for a lot of nothing. I wouldn't want to get on a plane if didn't have to in the current environment.
Do find Bale's behavior off the pitch a bit off color. It does him no favors, but then I guess he's a bit entitled after all the abuse from Z, RM, & the fans. Very poisonous relationship all around. As others have noted, surely a loan could be arranged, but it seems Flo-Pez has dug in his heels and would rather have everyone suffer. If I was in Bale's position, I'd probably be a bit more professional (like how Beckham handled his 'demotion'), but I definitely would not give RM any outs. After all the acrimony, I'd be sure to get all the money RM owes me, one way or another.