Does Mara Jade even exist in Disney canon? In old EU she certainly wasn't a Jedi during ESB.
But yes, especially with Disney canon the number of Jedi or "former Jedi and not Jedi anymore but actually basically still just Jedi" running around has gotten out of control. I chalk it up to the original trilogy vaguely assuming the clone wars had happened longer ago than ended up being written.
The Expanded Universe is not Disney canon. The Solo kids, Chewie, Palpatine clones, Thrawn, none of it played out the way it happens in the books. It is theoretically possible that between The Mandolorian episode where we see youger Jedi Master Luke, and the end of The Force Awakens where we meet Old Jedi Master Luke, that Luke met Mara Jade, got married, and fathered a child. But there was no mention of it in the new Disney trilogy or associated TV shows. So I would assume she doesn't exist until someone adds her to a story, and even then I wouldn't assume she would have the same role.
I think you misread my comment. She wasn't a Jedi in the old EU, and as far as I know she doesn't exist in new canon. So I'm wondering why she is on the list of Jedi running around, as no matter which continuity you pick, she doesn't seem to fit.
Yes, although that response image is about Lucas' supposed hate of Mara Jade as a character and less about her not being a Jedi. I know exactly what footage that's from.
I think they could conceivably tie in Thrawn with the efforts to clone the Emperor with the ST's interpretation of him coming back still. It was hinted in Mando already and I could see Thrawn being emboldened by the Emperor's return to start planning for the First Order or the dark fleet.