Bernie probably can’t reach a 1st ballot nomination with the remaining delegates out there. But he can deny Joe Biden a 1st ballot nomination. If THAT happens, then neither gets it. The DNC will go into brokered convention mode and all bets are off.
Predicting future is hard, but at least by 538’s models Biden has over 99% chance of getting a majority.
I think at least the part where Comrade Sanders will no longer be on TV is a blessing. He is poisoning the minds of impressionable youth.