There's already speculation that rather than recasting Kang Marvel will pivot away from him and fast track another villain. Doom is the likely candidate. No doubt they'll cast somebody safe, like Kevin Spacey.
He’s pretty young I'm sure he’ll find work and bounce back to some kind of career. I do get the vibes if we do see him again it be like a retribution kinda like Michael Vick had to rebrand himself and come back after a ton of lost followers/opportunities.
Can't say I'm all that sorry to see the character go. Majors gave it his best but I just never found Kang all that compelling or frightening. At least the version we got in the MCU.