Honestly, this is the kind of thing where you would need to be very careful. There's a reason why some fans are still bitter about the retcon of Gallifrey's destruction in Day of the Doctor and why a small handful of Classic Who diehards are still bitter RTD destroyed it in the first place - it's because if you're not careful it looks like a more personal attack than intended, particularly when the supposed "culprit" is unable to respond. Keep moving forward, I say.
Helpfully, there are fewer "events" in Moffat's tenure that I would consider unavoidable; Amy not knowing about the Daleks was a Big Deal because of how RTD had written the show with a specific timeline of events for five years; there's no real equivalent of that in Moffat's tenure. A modern-day companion ought to know about the Cybermen, and Gallifrey is a thing again, but otherwise as far as I can tell Chibnall and the rest of the writers have free rein (and the Doctor being married will remain a source of good jokes)
Also possible though I think Moffat would want to get the original actress if he could rather than recast, particularly considering they did just do the same thing with Alpha Centauri.
I still think bringing back Gallifrey outright was dumb, mainly because Gallifrey is crap - as the trip there in Capaldi's tenure showed. I actually think Day of the Doctor's retcon was a stroke of genius, mind, but I think Day of the Doctor, the mysterious assistance in Time of the Doctor and The Master's lie and the Doctor's self-destructive response to it in Series 9 was the perfect place to leave it for a
long time. Sadly, we couldn't. Urrrg.
Sometimes you do need to reset a bit though. People see percieved slights everywhere, but the "bits of history falling through cracks in time" fixed a long-standing Doctor Who problem, which was how everyone just seems to forget. In the old series you could sort of get away with it as the original show was very blinkered, but in RTD's 'slice of life' version of the world you couldn't write away the events of Journey's End or Death in Heaven, your brain wouldn't buy that people wouldn't remember... and RTD used the one final excuse with Donna (Martha, of course, remembered the Daleks and Cybermen).
But still.. I remember when Flesh & Stone aired people felt like this was Moffat issuing a fuck you to RTD. People are nuts.
I hope Chibnall does break away relatively clean, but there are a few things I'd like to see over the course of his tenure
eventually... like, I'd love to see Captain Jack, Ood, Judoon and River.
Ood just because I like them and I think they're fairly versatile as an ally or enemy alien, and River because I think the idea of her opposite a female Doctor suddenly makes seeing her again far more enticing. Judoon because... weirdly, I think the idea of them as recurring mercenaries, space-police, is a really good idea. I've liked that they've shown up a few times where that role makes sense in Moffat's era in background roles (The Pandorica Opens, A Good Man Goes to War, The Magician's Apprentice, Face the Raven)
Some of these you'd save for later years and you'd ideally avoid the characters in the first year, but I'd like to see them eventually. I think River is unlikely since literally nobody has written for her on-screen but Moffat, but I think Jack is actually probably more likely than ever since Chibnall and Barrowman get on and Chibnall ran the first two series' of Torchwood, I think.