WoW introduced the so called "bum mark" in 2005 already. You win a battleground, you get 3 marks for that battleground, you lose you only get 1. So yes, WoW does indeed give you a participation trophy. Also in WoW players died so frequently in PVP all around, you were bound to get a few kills here and there even as a bad player. Yesterday there were 90 minutes between two kills on the entire EU server during prime time. World of Tanks, which you're going to copy in NA Legends, gives a participation trophy on every battle. In low tier battles, this trophy is so low it covers all repair and ammo cost. Even if you die without firing a single shot, you get rewarded.
Speaking of WoT - that one actually does give non-kill rewards. Shoot someone down to half hp, you get rewarded for that even if he survives the battle. Will we see that in NA Legends as well?
If only that had come true...