Have we actually ever received an answer on whether specials aren't supposed to make sounds anymore?

Missing audio cues for specials and elites - #2 This is as far we got. I asked for a comment, an explainer, update on what if anything is being done to fix these close to game breaking issues. The issue was “acknowledged”, but we have had NO comment on this at all.

VT2 had / has some of those issues also. I would imagine some of that stuff is engine related, as those issues also happen when literally nothing is happening in the game, so it is not our sound cards getting overwhelmed with amount of audio.

For now you can use accessibility mods like Spidey Sense, which VISUALISES audio of incoming specials the same way Battlefield games visualise the direction of incoming fire:
https://www.nexusmods.com/warhammer40kdarktide/mods/268?tab=description