I feel like there will be a huge roster shuffle for next year because many rosters were formed very early in the game when players didn't know how should the game be played. This lead teams to have players who play the same in-game role. Nowadays, every pro has understood which roles need to be fulfilled in a team which are:
Atack side:
Entry: The first to enter a site (usually a duelist player)
Support 1: Set up the execs of the team (usually plays as controllers)
Support 2: Set up the entry+fragger with utility or help the team with info(usually play initiators)
Fragger: His main goal is to trade the entry( usually is pretty flexible playing with Sage, Skye)
Lurker: His main goal is to infiltrate enemy lines or to watch the flanks( usually is a sentinel)
Defender side:
Anchor A: Responsible for A bombsite( usually Controler or sentinel)
Anchor B: Responsible for B bombsite( usually Controler or sentinel)
2 man B: Plays more focus on the B bombsite, but have the freedom to roam the map ( Usually Initiator or flex)
2 man A: Plays more focus on the A bombsite, but have the freedom to roam the map ( Usually Initiator or flex)
Rotator: Can room the map as he wishes usually responsible for the middle when the map has one ( Usually duelist)