Do you have any information on who? I've mostly heard about players announcing they won't support it, and Apple and Spotify have their own analytics systems they'd probably prefer people use.
The big thing is Apple. Apple is definitely the big boy in the pond and NPR is in talks to get it working.
The thing is, if other podcatchers continue to refuse to provide data somehow, the advertisers are going to start refusing to pay for downloads and only for impressions verifiable on Apple, Spotify, and Google's apps. The end result is the closing off into walled gardens.
We already have Stitcher and Spotify buying up podcasts and keeping them exclusive to their platforms.
It can go either way but like...it's bad if it doesn't go this way. Either you're buying podcasts per episode or trapped on Google/Apple/Spotify's horrific podcast apps.
The apps are horrific. Google compresses audio to the point you get obvious quality loss and artifacting, even to my non-audiophile ears on $20 earbuds.
Apple Podcasts is a PITA once you've subscribed to more than 10 podcasts. It's really badly set up if you subscribe to a serial audio drama and have several seasons to catch up on.
Spotify thinks podcasts are just playlists in order from newest to oldest and wow is that a barebones and impossible UX for anything but a talkshow type podcast.