There seems to be a trend among the TV show runners (Filoni, Favreau) to try and redeem the Skywalker movies, so I could totally see this show runner pitching a show that would redeem the sequels just as Filoni worked to redeem the prequels. It’s a great selling point “hey I’ll make the hardcore fans like the sequels just like many of them now like the prequels” (never mind that the sequels made the prequels look good).
I’d actually kind of like there to be a theme of the Jedi being morally ambiguous, because that could lead to the attitudes non-Jedi have with the Jedi as well as the complacency we have with the Jedi when Phantom Menace rolls around - they could not wrap their minds around the Sith being back, and they let themselves be completely used by Palpatine and then got their asses Order 66’ed.
I actually wonder a little bit if the opening of the trailer with the kids is from the end of the series and he’s telling them “we didn’t believe the Sith were still around and we should have been listening to the Force”, even though the one girl mentions the bit about fire.
With that said, the show runner really loves the EU and said nobody pushed back on her using some big EU ideas (and arguably the biggest EU idea was Thrawn) and she said that she put some big EU ideas in the early and later episodes. I’d guess it was Sith-related lore, which brings me to this - there’s a lot of stupid fucking takes out there (especially the incels bitching about certain aspects), but I’ve seen multiple people dumbfounded that there might be Sith, because in The Phantom Menace the Sith were supposed to be extinct. Meanwhile, Palps is floating around and he himself had a Sith master, so there were clearly Sith still around,
I don’t think it’s Darth Plageus like some wonder, as the math doesn’t work out,