Over the years I have noticed that most alt season started as follows:
1. $BTC pumps first.
2. $ETH $BET & $LTC coin pumps next, leading indicators of the Alt season.
3. Big marketcap tokens next. Usually top 20 on CMC.
4. Then full blown Alt season.
I do fully agree with your assumption and I think this time around as well market will follow the same pattern so personally I am expecting the whole market to move big in the lateral part of the year till then the ground is clear for btc and eth to moon.