Altcoin season will start as soon as Bitcoin reach ATH. So this mean it can not even happen this year, but start in 2021. Or it can start at end of this year. We will fro sure not see Bitcoin AH before end of Autumn. To little time and to much resistance.
Most likely, the pump for altcoin will start in 2021. I suspect that this year a major recovery will occur. it will be seen when bitcoin reaches the price of $ 15k and ethereum reaches the price of $ 500. however, there is the great potential this year.