According to the law of market volatility based on Bitcoin Halving, bullrun times will be longer with each wave, this bullrun is expected to be 130 weeks, many traders predict that bullrun will last until June 2021. I also think that it is plausible, and as you said we have the longest bullrun ever.
$2T is a very high expected value as the BTC price is still going sideways around $35K, I just expect the BTC price to continue to stabilize above $30K so that altcoins have a chance to grow.