Hm... while this is certainly correct in terms of phylogenetics and taxonomy, I don't think a formal synonymy has been made for Dioxyna picciola to be switched to Campiglossa picciola. Han and Ro, 2019, attempted to do this synonymy, but did not properly synonymize the genera according to ICZN rules. Interestingly enough though, Systema Dipterorum has Dioxyna as still being a valid genus in itself, but picciola has been moved to Campiglossa picciola. After diving into it, I'd say go for it, but there is still a little fuzziness in the weeds of it!