If you queue as a premade in placement matches it will pair you with already ranked players for all 10 matches.
If you queue as a solo it will match only against other players in placements themselves for the first 2 matches and sprinkle in some already ranked players in the 1000-1500 MMR range (roughly bronze 1 to gold 5) for the remainder of the placement matches. Usually as a solo you play mostly other players in placements with just a few already ranked players when the system starts to feel they are a more appropriate match (like if you win your first 5 in a row it thinks you are more skilled than most new players and will start to pair you against high silver and low gold talent, if you win your first 9 matches as a solo it will start to pair you exclusively against gold players and no longer against other players playing placements.)
This was always true in previous seasons as well, so the problem is not exclusive to DQ, but it is exacerbated by the existence of DQ.
Its usually best for newer players to queue as a solo for initial placements (by initial I mean an accounts first ever set of placements, not the season reset placements which work differently) because the pairings will generally be more fair and even and you will have a much higher chance of having a random high level player smurf in your match to help carry your team. Of course the bit about having a high level smurf will also be true for the opposing team as well, so RNG is a factor here.
