Ah, that's true. While w3c still maintains a lot of standards, the intention to remove XSLT was sent to WHATWG.
I didn't look at all documents, but Working Mode describing how specs are added or removed doesn't mention users even once. It's all about implementors: https://whatwg.org/working-mode
I’m not surprised they focus on implementors in “working mode”, though. WHATWG specifically started because implementers felt like the W3C was holding back web apps. And it kind of was.
WHATWG seemed to be created with an intent to return to the earlier days of browser development, where implementors would build the stuff they felt was important and tell other implementors how to be compatible. Less talking and more shipping.
I didn't look at all documents, but Working Mode describing how specs are added or removed doesn't mention users even once. It's all about implementors: https://whatwg.org/working-mode