There is no "Player Assessment" at any point in Ranked. By this, I mean that the matchmaking system acts the same as Random Battles in selecting players and assigning them across teams in matches.
The only seperation that exists is in the form of Queues.
Imagine a situation where you had 3 Ranked Battle buttons. One Bronze, one Silver, and one Gold. Only Bronze is lit up and clickable as the start of a season.
If you Rank Out and qualify for Silver, the Bronze Button greys out and the Silver becomes clickable. You are now only able to play "Silver Ranked Battles" and you are matched using Random Matchmaker for this queue, just like you were with Bronze Ranked Battles.
In short, a different League is a different Queue.