No, they are not making, but it is valid to inculde a roundabout to route relations.

https://wiki.openstreetmap.org/wiki/Relation:route#Bus_routes_and_roundabouts
See bullet point 1.

You can also see in josm relation editor, that bus routes have no gap at the roundabout, and also relation analyzer tools accepts this solution.

But note, that iD is buggy and often spilts roundabounts again.
