I think evidence which does not belong to currently known individuals (even new teeth) requires to name a new organism in order to differentiate it from the other organisms known in our discourse. If later, with more complete remains, it turns that the little evidence formerly used to erect a taxon, actually can be assigned to various possible distinct taxa, the name can be just discarded.
What do you mean by "just discarded"? Validly published names have priority over junior synonyms and junior homonyms forever, unless specifically suppressed by an Opinion of the International Committee on Zoological Nomenclature against one particular junior synonym or homonym. Their holotypes remain holotypes forever...
...and "nomen dubium" is a taxonomic concept, not a nomenclatural one, but the ICZN is about nomenclature, not taxonomy.