Maybe it will come back again. But not all altcoins will come back. To my mind, only the top 100 altcoins will return in 2020, and all the rest will die because it doesn't have any benefit.
it's too extreme in my opinion,
I look more into the project, even though altcoin ranks above 500 in CMC, but if team is still developing, community is still strong then it is possible that the project will be moon when bullish has reached its peak.