It's a little odd that the second paragraph of the article cites how rats "may have transmitted plague" and then links to an article titled "Maybe Rats Aren't to Blame for the Black Death".
I think both phrases do a good enough job expressing the uncertainty of the rat's culpability in the black death: "X may have Y" and "maybe X didn't Y" are two sides of the same coin.
The "common knowledge" is that rats (or their fleas) transmitted the plague. New research suggests this might not be the case.