Externalities, Pigouvian Taxes and Wikipedia
The Pigovian taxes are non-distortionary. For example imagine situation where government optimal spending is 100e and before Pigovian tax all 100e was raised through income tax which creates distortions on Labour market. Let’s say that after imposing Pigovian tax government gets additional 30e. Now since government needs only 100e for its optimal spending it can either choose to run 30e surplus or choose to reduce the distortionary income tax by 30e. The Wikipedia sentence refers to this second option where government chooses to reduce some other distortionary tax thanks to the revenue from Pigovian tax.