@passwordnow
Correct, several pro players have dropped to a lower tier before. The last player I can recall with such a high-profile on the CS2 scene was Kirill Mikhailov aka Boombl4 which was also on NaVi. I remember watching his comeback to the counterstrike scene over a year ago where he was playing with a team nobody ever heard of but he eventually settled with Betboom after several months.
The group stage also ended yesterday, and this time we could have a Spirit vs. Vitality matchup in the grand final, assuming Team Spirit and Vitality don't underperform while waiting in the semifinals.

The
quartersemi-finals are almost set but we have to wait until Friday's
quarter-finals results between MOUZ vs FURIA & The Mongolz vs NaVi to see who Team Spirit and Team Vitality will face the next day.
I would say FURIA will advance since they have been playing lights out from all their matches I have seen so far.
And probably NaVi since Mongolz have been disappointing in their last match yesterday. So the momentum is just not there for them to move forward.