Farage is in the same position as the Tories currently - he can say whatever he wants because he's not in power and has no responsibility to anyone.
I would be wholly unsurprised that if Reform won a GE and Farage became PM, anything he said before that would be unceremoniously dropped (see: almost every politician who gains power) and, frankly, Farage goes full Trump and, e.g., applies the OSA to censoring everyone he disagrees with.