The Ny’alotha raid was somewhat unique in that we needed to have our legendary cloaks levelled up to resist corruption in order to fight Carapace + N’Zoth itself.
If our legendary items (cloak, heart of azeroth) are deemed as unnecessary and outdated as we move into a new expansion, the boss mechanics in raids should also be tweaked with as to not require these outdated products. Not only is it old/legacy content, but it’s also “borrowed” power that we shouldn’t have to go back and keep borrowing. (On that note, notice how in islands we still use our “neck” to absorb Azerite on the ground? Funny how that works since I’ve ran some alts through there who never touched BfA content.)
There is precedent for tweaking old raids to make them more solo-friendly once the expansion has gone by the wayside: Razorgore in BWL, Hellfire Assault in HFC, Eonar in Antorus, also the chess event in Karazhan was tweaked so it can be easily solo’ed.
I understand that people still level through BFA, want to do the questline, experience the content, etc. still, but that doesn’t mean that we can’t go back and make things more solo-player-friendly. Someone new to the game may not want to bother spending the time/effort to grind their cloak out to max level resistance just for old content when the Shadowlands (and Dragonflight) await them.
Other things off the top of my head that have been overlooked and for some reason still exist in their current form:
-Ordos on Timeless Isle STILL requires someone to make the legendary MoP cloak (which you can’t even make anymore as a new player) in order to get over to the Sanctuary to defeat him.
-Viscidus in Temple of Ahn’Qiraj requires FROST damage to die. Really trivial boss from a raid that was implemented before some of the people reading this post were born.