Rugby Morning folks confirmed on the r/MLRugby discord that there will be 6 matches on ESPN2. Also the conference finals and championship will be on ESPN2. So it sounds like only those blessed with a cable subscription package for ESPN2 (including Hulu Live, YouTubeTV, etc) will be able to watch the conference finals and championship live (other than actually physically going to the matches, of course).
edit: - Rugby Morning team just said on discord that they're hearing "matches will air simultaneously". So that at least brings the paywall down to just ESPN+ price.