What do high-ranked/challenger streamers/players/pros know about Griefing?

Usually when the stakes are higher in higher-ranked games, players have tendency or more incentive to not attempt to grief.

Have these "challenger players" experienced -

1. the Tahm Kench who swallow teammates to spit into opponents for slaughter...
2. the Anivia who repeatedly used her wall to block off own teammates' retreat route...
3. the Ryze who repeatedly transport teammates into enemies to be slaughtered...
4. the Janna who only pushes teammates to enemies...
5. the Taliyah who walled off own teammates retreat...
6. the Bard who repeatedly helped enemies catch up on teammates via magical tunnels...

I really doubt these Challenger Players have experienced Griefing of such nature. Being that they mostly play on high ranked games where stakes are higher and where their games have a more "visible" nature... i.e. being seen by others on streams etc.

If they did, streamers such as NightBlue3 would not call out to Nubrac's strat as griefing.