Yes it started with Double Goblins but you are wrong about when or why.
It started in Mid- Season 20 April 17, 2020 - after lockdown orders and everyone working from home.
WoW XP buff started March 20th to April 20 - start of COVID - then they extended it for the rest of the summer and fall until SL release. This was in large part for folks stuck inside gaming.
So, seeing as they extended the WoW buff, we got the double Bounty thing for Season 21. We also asked about it on the forums quite a bit
