There is a fair amount of tag synonyms that are created via the child meta (in fact, looking at the tag synonyms page, the vast majority of the synonyms are done by the mods).
- Merge [video-conversion] → [video-converter]
- Synonymize [ahk] with [autohotkey]
- Merge the tag "test" with the tag "testing"
Why should the users that get a status-completed on their post not get the badge, just because they suggested the synonym in a different place?