This seems quite straightforward to me, though looking at some of the Gaura observations the name change appears to have been a little contentious...
Just wanted to check in with a few folks before committing the taxon change.

@crx2aj3
@alexiz
@stevejones
@annemirdl

Odd that Gaura coccinea was in the GBIF database three times, though maybe not unprecedented. Given the preponderance of authorities you list (and add Jepson) this looks to me like a valid change, even though The Plant List only recognizes Gaura coccinea. That's probably the source of any contention you saw.