Why did Sen get the first Map pick?

Did they do a toss for map pick? Shouldn't it be the team from the upper bracket getting the advantage? Lev came from the upper bracket they should have gotten the first pick, no?

they are on equal footing it should be a coinflip lol

Traditionally teams prefer to be team B to ban and pick 2nd.

Since they might ban a map you wanna ban and you've got your own map pick to fall back on if you lose game 1.

So Lev most likely chose to be team B