Another good example of this is GTK. When GTK 3 came out, there was a bit of fighting over accessibility, but nothing alarming. The GTK folks were generally happy to make the toolkit in a way that it had built-in accessibility support. Default widgets came with accessibility from the get go, a bit like html 5 does nowadays for websites. And it was great this way.
When GTK 4 came out, on the other hand, things had shifted. No longer were the GTK people happy to provide accessibility for us. No longer did they care about it. Their grand plan was to remove accessibility from GTK altogether, claiming that it was up to the applications themselves to become accessible. It took several weeks, and even days during fosdem for them to recognize this wasn't the way forward, thanks to the orca developer and the Hypra folks, but they got the idea. Or did they?