The post indicates WHATWG has "broad agreement" about removing XSLT. I don't know how many seats Google has there, but on the surface it doesn't sound like a unilateral decision.
The XML proponents lost this fight a long time ago. Without continued development, the user base shriveled up. Now that no one uses it, the runtimes are looking to cut dead weight.
I disagree with the pivot (RIP noscript) but it's not Google making this move unilaterally. It's been in the works for a long time.