To reference some things already said, I also never thought of TMS as a parody, but as a legitimate variety show crossed with a backstage sitcom. You might call it a hybrid variety show / sitcom.
In my opinion, the last few attempts to revive the Muppets on TV haven't worked in part because they were trying to make a show that was TMS but wasn't TMS. TMS was so successful that they tried to keep the basic formula that made it successful (variety show with sitcom elements to enrich the characters) but update it and "make it more modern", which never quite worked, either on JHH or MT.
To my mind, this left them with two alternatives: either revive TMS straight-up, with the same set, format, and anything else they can replicate; or, don't try to preserve the TMS format at all and go in the other direction. The latter seems to be what they're after, and I admire that.
As to the how it's looking so far, I have to be the voice of dissent: I did not like the trailer.
Simplifying Miss Piggy's selfishness to the point that she no longer remembers the names of any of her co-stars, save Kermit, is changing the character. Yes, they're not exactly canon and such a change is not exactly "retconning" (retroactive continuity), but it is changing the character for the sake of a (cheap) joke. And if you have to change the character to make the joke work, then the joke doesn't work. Prady's other baby, TBBT, has been accused of this kind of oversimplification of character increasingly in recent years, from making harshness Bernadette's #1 new trait to reducing both of Raj's girlfriends to one dominant character trait and nothing else (Lucy is socially awkward, Emily is scary; and that's the sole basis of characterization with no attempt at depth or complexity).
Then there's the "adult" content. Joking that the band was on drugs: too easy. Offending Fozzie with the "does a bear s--t in the woods" line: can't even spell out the basis of that one here. Kermit being attracted to pigs (something he's never admitted before) and Piggy's rival nibbling on a phallic symbol (the pencil). It all just seems like cheap, easy jokes from here, going for the lowest common denominator without much creativity or attempt to make the humor intelligent.
I did appreciate the "bacon-wrapped ****-on-earth" line, but that's about it.
We'll see.
David "Gorgon Heap" Ebersole