Fox calling the election is, if not a confirmation, a strong indication there won't be a fight over the legitimacy of Biden's win - Fox is the mouthpiece of the GOP. If it there is contest, it'll be through Trump himself, his loyalists, and party outsiders, not them.
If you've ever seen Casino, the GOP views Trump like Remo Gaggi saw Ace Rothstein/Nicky Santoro: Trump's given them unprecedented victories and allowed them to pull off all the normal republican shit (tax cuts, judges, etc.), but he's a wild card and their missions are fundamentally different. The GOP was always antsy about Trump's heterodox, anti-establishment, populist-nationalist characteristics and never intended to act on them. With a one-term Trump, they get control of the Senate and all the stuff they intended to do, but can spend 4 years coasting on rage against DUMBOCRAP SOSHALIZUM instead of doing the harder work of Trump's positive vision.
I think Dyin' Mitch and Sleepy Joe might actually be perfectly happy as
America's new power couple. As for Trump, hope he has a metal plate in his Caddy.