"Once you've got a red chair, you always have a red chair," Burnett told ET's Nancy O'Dell on Wednesday. "Coaches go on tour and make albums. This is the challenge of The Voice, is fitting into the schedule of these currently top-selling artists... [but] we love all our coaches."
With hit after hit on TV, Burnett has seen it all -- including Stefani's blossoming relationship with fellow Voice coach Blake Shelton.
"You know how great that makes me feel, that two of my favorite people met at The Voice in those red chairs?" he shared. "They're so in love, and I love them. There just a great, great couple."
"Gwen and Blake are exactly the same," he added. "Cameras on or cameras off, these are two sincerely loving, fun, brilliant people."
While Stefani (and Alicia Keys) won't be back for season 13 of The Voice, Burnett and his team have found a couple of powerhouse replacements -- Jennifer Hudson and returning coach Miley Cyrus. Hudson's fellow American Idol alum, Kelly Clarkson, has signed on as a coach for season 14.
"It's amazing to have both Jennifer and Kelly. I've known Kelly for a long time, and Jennifer is amazing. I've worked with her on award shows before, and you saw she performed last week on [The Voice finale]," Burnett said.
The Voice was a big ratings win for NBC on Monday and Tuesday, before Wednesday's season finale of another one of Burnett's shows, Survivor, on CBS. On Thursday, Burnett delivered another hit as Beat Shazam premiered on Fox, and on Friday, Shark Tank returned on ABC.
New to Shark Tank this season is baseball star turned entrepreneur Alex Rodriguez -- who also happens to be dating Jennifer Lopez.