Yes and no. If everyone who expects a crash has sold already, and there wasn't a crash yet, how could it trigger one?
The stock market has been found to behave completely randomly, even when taking into account all available information.
Yes, there was a crash at the beginning of COVID-19, and the market recovered disproportionately to the amount of pandemic-related destruction. There are also many really bad things that happened and did not cause crashes. And there are crashes that happen out of nowhere.
They say that esteemed economists have predicted 92 of the last 5 recessions.
More money flowing away from the market into safe(r) investments than flowing in causes valuations to plummet.