With the season well underway, I figured it would be a great time to have look at PvP participation in the Shadowlands expansion. For this analysis, we collected data from 40,000 (pseudo-) randomly chosen characters from all US and EU realms. We excluded characters that were not level 60 or hadn't logged on since the start of the season.
Rated PvP participation is defined as having played at least one game of rated PvP content. If there is no mention of a specific bracket, participation is defined as participating in any type of rated PvP (i.e. 2v2, 3v3, or RBGs).
Approximately 31% of all level 60 characters have participated in at least one game of rated PvP. 2v2 is by far the most popular form of rated PvP content, with 27% of characters having participated in at least one game of 2v2. Half of these characters (13.5% of all characters) have played more than 50 2v2 games. The second most popular form is 3v3, with 18% of characters having played at least one 3v3 game. Half of these (9% of all characters) have played more than 35 3v3 games. US realms have an overall higher rated PvP participation than EU realms. This effect is seen across all forms of rated PvP content.
Healers and melee participate more in rated PvP across all brackets. Anecdotally, healers experience a much easier time finding groups than DPS due to there simply being fewer healers to go around. This may account for the high participation among healers in rated PvP.
The relative lower participation of ranged DPS may be partly due to the fact that melee specs are doing fairly well in PvP, with Arms Warriors, Windwalker Monks, Subtlety Rogues, and Retribution Paladins all being highly represented in high-rated 2v2. On the other hand, traditionally strong ranged PvP classes such as Warlocks are doing relatively poorly in the current season, and so the overall weaker performance of ranged specs may account for this group's lower participation.
Classes that have been strong this season tend to have the highest participation. Rogues, priests, paladins, monks, and warriors all have at least one very strong PvP spec and constitute the classes with the highest rated PvP participation. We see extraordinarily high participation among rogues: over 40% of rogues have either stepped into the arena or a rated battleground. This probably reflects that Subtlety was very strong early in the season (i.e. one-shotting people is fun) before receiving a significant nerf.
Classes that are currently weak in PvP - hunters, warlocks, demon hunters - have low PvP participation. Interestingly, one of the weaker PvP classes at the moment - death knights - have relatively high PvP participation.