I can see a problem with that. Gpx tracks are seen as a form of raw data in osm and it is not desirable that you edit your traces before uploading to osm. Traces in Mapillary are quite often heavily edited (and there is no way to tell if this happened) and thus shouldn't be uploaded to osm.
The danger is that when you upload a Mapillary trace that's edited with the help of a osm background, someone will later us that trace to improve the osm data. And voilà, you've created a circle jerk.
I've posted this before in a discussion about this subject at https://github.com/mapillary/mapillary_issues/issues/388