Blizzard seems to be testing how far the players will go for the Epic skins without paying for them as the two latest events changed the rules a bit.
Archives 2021 introduced a new way to earn skins through gameplay as it required doing the associated PvE activities and collecting performance stars in order to unlock the cosmetics. Previously, the skins would be earned through scoring nine wins in total but it looks like this system is going to be significantly changed in the future.
With Anniversary 2021, there is no option to complete a challenge by winning nine games, and therefore being able to get the skin on short notice. Instead, players will be forced to play between 14 and 27 games for the unlock.
The change may still look innocent enough since this system would require slightly less than four games a day on average but keep in mind it requires ~55 per cent more games in the best case scenario, going up from 9 to 14. Furthermore, this looks like a case of boiling a frog slowly as we've seen these things happen countless times in the gaming industry.
For example, Destiny players could initially get most cosmetics out of Eververse without paying for them but these days, all the cool looking things are locked behind microtransactions and even quality of life features are either paywalled or require massive grind .
Anyway, it remains to be seen how the fans will take the change to the challenge system and whether Blizzard continues down this road leading up to release of Overwatch 2.