I respect your stance here and I can understand why folks want something like this.
That said, I think it would have some consequences that I’m not certain everyone would want.
Take the current difficulty built specifically for matchmaking - the “Looking for Raid” difficulty.
Until those queues get populated by a large portion of folks who overgear the encounters, it’s a messy affair at best. The determination buff’s existence tells us Blizzard’s metrics show trends toward failures. Not terribly hard to recognize in my experience - people tend to just try treating every encounter like an older generation world boss with very little in the way of mechanics or consequences for failing them.
Imagine what would probably be in the pipeline if normal AND heroic were matchmade content. Now, would the determination buff still exist? If so, to what extent? When does that start to cause friction with groups organized using a guild or the group organizing tool.
Feels like lately, Blizzard has been monitoring such friction and adjusting. I don’t have an ear inside the design team, so I can’t say with certainty that they are doing something as a direct result of friction or vocal feedback on a system, but I think it’s possible when we see some changes, like movement of higher tier crests substantially on the mythic plus ladder. Doesn’t mean it was done for that reason - might have just been a change owing to the difficulty consolidation, but not sure why they wouldn’t have done it in Dragonflight as well.
Further, I think we would then see a necessary change to encounter design, hotfix/patch adjustment scope, and difficulty if those higher difficulties became matchmade content. The fact remains that any sort of matchmade play just isn’t as innately organized as something done manually in a guild or even via the bulletin board, so would Blizzard just leave those queues to potentially flop endlessly and thus have low populations, making it a debt feature they have to maintain for little engagement? I’m not sure, but that’s my primary worry - there is a reason right now that Blizzard has continued to name the matchmade raids as their own difficulty - meaning it is designed and tuned around a disorganized (and yes, lower item level) group.
I don’t see them forcing voice chat, there’s no guarantee everyone has boss mods or even looked at anything from the dungeon journal to a video or website to learn the encounter - how much churn will groups tolerate as people cycle in and out after being vote kicked for not having a solitary clue, and how long will players who do these things keep doing them via this queue when they lose rolls to people they feel somewhat slighted by as they either died or failed mechanical requirements several times? I feel like those players, core to making sure a matchmade game mode survives, will just go back to the bulletin board.
This is just my concern. Again, I do not disagree that matchmade content is more or less “the future” as most games these days (mostly pvp games though) deploy a matchmaker. I think for what you are looking at with heroic and normal raids, heroic at least is probably better off sitting out the matchmaker and perhaps normal would be adjusted for it, but I’m not certain. I just think in light of some of these issues, we would see a queue that both creates some issues (fundamental changes to normal and/or heroic encounter design and difficulty; a difficult queue to keep healthy) and would perhaps muddy the landscape a bit, especially for a newer player who has no idea what is the difference between all of these different means by which you can engage with the raids. Last, I do think it would be hard to keep these queues healthy.