No government was ever focused on destroying regional languages. The unilingual schooling system was already established before the Revolution, 19th c. governments only enlarge it. The real cause of the disparition of regional languages was the urbanization of the society, not an evil plan.
There are accounts of schoolchildren being (lightly) beaten for speaking Occitan instead of French in school. If that doesn't sound like a deliberate policy of suppressing regional languages, I don't know what does.
Much in the same way Esperanto was, so a revolutionary auxiliary language of course in more then one way haha.
Maybe a creole could come about somehow.
Creoles don't really work like that. You need a superstrate and multiple substrates, which requires a level of concentrated linguistic heterogeneity that doesn't exist in France at the time. You could get a mixed language, but that's different from a creole.