Amidst the doom and gloom of Mercedes favoring Antonelli and not wanting George to win, so all hope is lost, I offer a little counterthought.
First, the premise: I really doubt Toto loves Kimi and hates George. He loves money, spectacle and a narrative that portrays him as the best TP ever. He'll get behind either driver if it suits his ego.
Therefore, for one, Mercedes needs to get the WCC. It's embarrassing that they were outclassed by their customer team two years in a row. They need George's car at least functioning for that. It may seem like they don't realize or care about their faults, but their attitude is a cover up, a diversion. They've done this plenty: "hey, don't look at this ugly blunder, look at this shiny thing instead, aren't we just awesome?". They know they messed up, but they'll always pretend they didn't.
For two, sure youngest whatever is cool, compensate for the miss with Max, yada yada. They can still get that for the next three years, though. You know what else is cool? Largest point deficit ever overcome to win a driver's championship*. And George would take it by a lot.
Just last year, Toto was saying that he didn't think Max was the only driver who could close a huge point gap, that Red Bull had improved a lot to help him and so on. He also seemed almost giddy at the idea of managing another intense intra-team title fight in Canada this year. He takes great pride in handling the Lewis-Rosberg years — although, what he has to proud of in that I do not know. Furthermore, Toto may sound borderline senile often, but he's not stupid. He knows George's quality as a driver.
Bottom line is, if George can shift the momentum — and he can can, he's the better driver by a margin and already came close to taking the wins in Japan and Canada despite several issues — there's a real possibility that Toto and Mercedes will back him up, at least enough to let him drive. Because that would be one sexy narrative, with Mercedes front and center in every way. And if George fails, the wonderkid takes it, so it's a win-win situation. Whether having the support of an incompetent team can successfully lead to this outcome is another story.
*The point deficit record is a bit complicated with the change of point system. I believe adjusted the largest in the modern era would be Räikkönen in 2007 with 56 or so. It also varies a lot in amount of races still to go. In any case, records in F1 are simplified to what gets the better headline, so it would be the larges ever for sure.