Yeah, they underperfom for a bit of time, which isn't so good. Teams can have bad matches or days or even weeks, but it must end sometime, and if not now for G2, never.
Also, Navi is at least for me best team atm
I don't know what about Gambit, they had a good year, but remember "had". They can start underperforming as well.
And maybe ence is black horse (I hope ;)