There’s a few hot topics on this if you’d like to check them out.
https://us.forums.blizzard.com/en/wow/t/wont-fix-scaling-i-wont-renew-my-sub/793290
https://us.forums.blizzard.com/en/wow/t/one-month-in-legion-still-not-properly-scaled/787505
https://us.forums.blizzard.com/en/wow/t/old-content-scaling-and-ions-response-in-qa/777441
https://us.forums.blizzard.com/en/wow/t/old-raids-wont-be-fixed/784141