I don't know why people insist that just become someone paid money to the original writer, they now have the authority to rewrite the story and somehow it is cannon.
Disney pushes a lot of shit tier fanfiction that they claim is "canon" because they have a lot of money. But we the audience do not have to accept that.
Its not just "Here's some money, we're going to change some things". Its about who owns the rights to a character and in turn there's licensing concerns. Believe it or not, comics themselves don't make a huge amount of money, most of the money earned comes from merchandising. Comics are often a tie-in to another medium, designed to promote said medium, where a licensing agreement allows the publisher to use the characters in whatever way they want, from crossovers to their own comic. But if they end up losing the license, well they can no longer use the character or reference them properly, not without paying a large penalty or even being brought to court. A famous example of this was Rom: Space Knight, which was a 1979 toy from Parker Brothers. Marvel had the license to publish a comic based on it, and the comic lasted several years longer than the toy itself and is a favourite to the point that more people knew about the comic than the toy. But eventually, Marvel lost the license and they could no longer use Rom...but they could use other characters that Marvel had created for the comic (basically Marvel built everything from the bottom up for the comics). They can use those characters, but if they wanted to use Rom? Well that's a hefty fee to Hasbro and it's probably not worth it now.
Something else to understand here is that the comics industry has been pretty shitty to creators. Its an industry where just because someone created something doesn't mean they actually or automatically own it. A lot of creators are brought in on what's called "Work for Hire", which is a copyright term that basically works on the idea that a publisher hires someone specifically to create a character so the publishing company owns it. The writer or artist got paid to create something but they don't own it.
To be honest, the two big comics companies are notorious for screwing over creators, one of the most infamous examples was Bill Finger, co-creator of Batman. While Bob Kane's original idea for Batman was a guy in a red bodysuit, a domino mask and with wings on his back, it was Bill Finger's input that created the design we recognise today, but because of his status as a writer, he was screwed. He died in obscurity in the 70s and it was only in 2015 that DC recognised his contributions and officially accredited him from then on.
Which just goes to show, there's a whole lot more at play than "just giving someone money". There's
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that explains some of this with a better legal understanding than I possess.