Pretty sure they made the announcement hours before that they changed the “Patch” for the fated raids. Raid Rewards Experiments in Season 4 - #761 by Kaivax Kaivax’s post was only 29th this was really the only hint that it was coming They didn’t hotfix the achievement Until Aug 1st these achievements have been in live since MAY 31ST.
https://www.wowhead.com/news/season-4-fated-raid-achievements-hotfixed-to-include-normal-difficulty-or-higher-328111?webhook (Seen here for when it was hotfixed)
And while yes this older post information relates to the ptr they did nothing to even imply it was normal and above due to the fact it says complete all “FATED” Raids… There was and IS a FATED LFR… https://www.wowhead.com/news/jig..glesworth-sr-slime-cat-mount-for-completing-all-season-4-fated-raids-326882#comments
Again this is the principle of the thing of just telling us Officially (insert Angry words here) people who only do lfr a very short time before it going live.
Yes… I am angry and I will continue to be. (and you will have to remove two … from that 3rd link beacuse apparently jig…glesworth is an issue?)