ETH is better than bitcoin in so many ways. Moreover, faith in BTC is starting to run out as transactions get heavy and expensive, making it harder to manage. The soft fork going on on Aug 1 is scaring holders too, which are jumping on ETH, which still have so much to give (Metropolis, switching to PoS, ICOs,...).
Conclusions: it's not about whether the flippening will occur or not, but it's all about WHEN.
My guess is within 2 months.