I'm not sure the flippening would actually happen, but people will start speculating about it again for sure.
It's possible too. The ETH supply is growing a lot faster than the BTC supply, so overtaking BTC's market cap is getting easier and easier in terms of price. Market cap is such a dumb metric......
There are other metrics too - the number of transactions per day, adoption in a wide variety of ways, the number of businesses built on top of the coin. Ethereum has a lot of stuff built on it's platform, whereas the lightning nework was supposed to have done the same and has failed.