First off; for better or worse the company has gone to great lengths to at least give the appearance of honouring George's legacy. So the odds that they're going to "erase" any of his work, much less one of the last things he did before retiring are decidedly slim.
Secondly, Kennedy is not the driving creative force at the company. She's not the Kevin Feige of Star Wars. That's not how Lucasfilm operates, any that's not likely to change no matter who gets that job next. It's mostly a supervisory and administrative position. The gig is mostly to oversee the business side of things, not hand down narrative dictates.
1) That's not going to happen. 2) If it did, who cares? All canon really means is that the new stuff should pay attention to it. If the franchise gets to the point of no longer making things that consider those shows in-continuity they it would have likely strayed so far as to be unrecognisable, in which case the "new" stuff probably won't really be Star Wars anymore. So again; who cares? "Canon" is not some magical property that once removed makes a thing cease to exist. It's just an arbitrary label and should be treated as such.
Anyway, all of this is stuff that isn't likely to even be a remote possibility until at least another 20 or 40 years down the road. Colour me unconcerned.