I don't think Syke is the best on Icebox and on Bind Liquid use to put Soulcas on Skye but in the grand final against Giants he did well on Raze so I guess they are continuing with that. And I guess Navi just doesn't run Skye on Bind.
It's actually unbelievable to me, that they revealed their strat in challengers 2 seeding game(which put them in a harder bracket) and now they are trying to pull it here.
Way I see it is that Skye is almost mandatory on every map except Icebox, but she is still viable on that map. Similar situation with Sova on every map aside from Split of course, but even he can be played on that map.