If they really nerf him, I've lost all confidence in their balance team.
BTW: Winrates DO correlate to a champion's power when looking at high ELO. This is indisputable and has always been true. They aren't the full picture and there can definitely be outliers due to low pick-rate (ex: Heimerdinger), very high skill-cap etc. but in general, it's quite reflective. In fact, even Riot's nerfs tend to attack the higher winrate champions so to say otherwise makes no sense.
Pick/ban rates are often FAR more inaccurate than winrate when looking at strength. Banning stuff like Ekko or LB makes very little sense these days. Their performance is abysmal except in niche scenarios (like Ekko JG which is pretty average). The same goes for the recent Runeglaive Ezreal which is banned a lot but again performs poorly in every ELO (47% even in Diamond) and has more of a frustration factor than objective strength imo. The lack of CC, slow ramp-up time, almost his entire kit negated if body-blocked by tanks/minions, low pushing power etc.
Bans are more emotional and about preference than what actually makes sense. WW even remained a common ban long after the nerfs to him and Devourer. High pick-rates also don't mean a champion is particularly strong and may be just due to entertainment/play-making like for Lee Sin.