I think people kept it taboo for as long as they could because: people were literally dying due to low vaccination rates, which were caused in large part by such specious conspiracy theories. Fact checkers did not do a 180, it is still widely considered a conspiracy theory, and its very existence harms public health even if there's a remote possibility it's true.
“Some scientists agree that the possibility of a lab leak should be examined as part of the ongoing investigations into the origin of COVID-19, though they have expressed concerns about the risks of politicization.”
The Wikipedia article is frankly disgusting. The two options are natural origins or leaking from a lab and currently there is more evidence for leaking from a lab. There is no debating this. The Wikipedia article has already chosen a conclusion with no evidence and also is slandering the other possibility for political reasons while simultaneously saying that it can't be the other potential cause because it might be politically motivated. Absolutely disgusting. I expect better from Wikipedia
This reads like a lot of mental gymnastics attempting to excuse the inexcusable.
You argue that blocking debate is a righteous act because the theory's "very existence harms public health". I'd counter that the gagging of a concerned public breeds distrust that is vastly more harmful than allowing debate would have been.
Unfortunately this wikipedia article serves effectively as yet another type of political "fact checking". Multiple virologists have stated that the only evidence in existence currently points to a lab leak. Labelling it as a fringe or destructive "conspiracy theory" is complete BS and it's not even conspiratorial, it's called a mistake and lab leaks have happened in the past.
https://en.wikipedia.org/wiki/COVID-19_lab_leak_theory
“Some scientists agree that the possibility of a lab leak should be examined as part of the ongoing investigations into the origin of COVID-19, though they have expressed concerns about the risks of politicization.”