It is not.
The way it worked was that the CDN specified server (eg. &cdn=video20.dfw01.hls.ttvnw.net) was changing the insides of the M3U8 playlist. Adding the server specified by CDN to the path of each TS (video) element.
Here’s M3U8 Playlist with CDN (before they removed it):
And here is M3U8 playlist with CDN removed:
This forces the player to use local server, ignoring CDN.