What's the highest you can get out of placements this season?

For seasons 4 and 5, the highest you could get out of placements was Plat 1. And let me tell you, plat 1 those first few weeks were a nightmare. Everyone from challenger to Diamond 5 was in a single bracket, playing against each other. And because Diamond back then had a very exponential power curve, Games were decided by how many challenger and diamond 1 players you'd get in your game.

But in seasons 4 and 5 there was no master tier, and that opened up a LOT of space in Diamond. No longer is the skill difference between a Diamond 5 and a Diamond 2 equal to the distance between Bronze 5 and Diamond 5. Though it's still not quite a smooth progression, I'd say now it's closer to the difference between Gold 5 and Diamond 5, but still, because Master exists there's no-longer a reason to make the Plat 1s and Diamond 5s play with the challengers on reset day.

So this year, is Diamond open to placements, with Master and Challenger players being put in Diamond 1 instead of Plat 1?