I don't think either Animal or the Swedish Chef have mellowed out. I love both of them as much as I always have and I'm thrilled that both are as prominent in the Muppet cast as they were in the Jim days.
I'm honestly delighted with the continuity that Eric Jacobson has given to Animal (if it weren't for Muppet Wiki I wouldn't be able to tell where Oz-Animal ends and Jacobson-Animal begins). I loved him in the virals - especially "Bohemian Rhapsody," where he's an absolute STAR - and the new movie. Both projects saw Jacobson commit fully to all sides of Animal's character; even when he was going through identity crises ("Mama? Dada?") or trying to figure out whether or not to drum, he was still unmistakably Animal. It wasn't like Robin Williams spending the entirety of Popeye grumbling about how much he hated spinach.
Bill Baretta has reinvigorated the Chef in a fashion I truly didn't see coming. Loved him in the virals, A Green and Red Christmas and The Muppets. Nothing wrong in the least in showing his softer, chicken-hugging side (remember his duet with Big Bird in MFC?). The Chef is a loveable goofball with a bit of an ego problem, and he always has been. No worries in this corner about giving him more than one layer - that's what Jim always did.
And what's this about the Chef losing his edge and "not running around with cleavers anymore"? What about the "Opening This Thanksgiving" trailers for the new movie that had him chasing down the turkey (and vice-versa) - likely the same turkey he threatened in "Bohemian Rhapsody"? What about the flamethrower scene in The Muppets (with the great line "Say hello to my little friend" in pidgeon Swedish)? That's not edgy?
Finally, to Slackbot: Excellent Weird Al lyric quote. When I saw him live in 1995 I made a sign saying "Weird Al Sez: I'll Be Mellow When I'm Dead." Since I was sitting front-row centre, I sure hope he saw it.