The first week of 6.2 is coming to a close. As of this moment, 10,231 guilds have downed the first boss of HFC Normal, as tracked by wowprogress.com.
In contrast, 57,430 guilds are recorded as having downed Kargath N. In the first week of tier 15, 15,189 guilds had downed Jin'rokh on what was then called Normal mode (what is now Heroic).
Raid participation beyond LFR appears to be in serious decline.