And hadn’t it already been established that Qui-Gon couldn’t appear “in the flesh” because he hadn’t completed his training before he died? I’m sure this was explained in one of the cartoons.
The 2017 book From a Certain Point of View showed that Qui-Gon had learned to appear in the flesh by ANH (but it took a lot of effort to do so). All the show changes is that Jinn knew how to appear in the flesh a decade before it happened in the book.
So they have altered canon yet again just for a few seconds fanwank? Jeez
Not really? Nothing in the book says that Jinn couldn’t have done it a decade earlier (it doesn’t imply that his 0 BBY appearance is as the first time). Besides, there’s nothing that says that a force spirit can’t learn to physically manifest if they couldn’t before.
The book messed it up first, if one takes a negative view of the physical Jinn ghost.