Obviously the person to ask is Test Pilot Eric 'Winkle' Brown, though he is very clear in his books and lectures he reckons the M.52 was cancelled purely for political reasons ( smarming up to the U.S. ) and large parts of the design, especially the flying tail, were indeed robbed by the Americans, who then promptly refused a reciprocal visit / info' exchange.
It also strikes me that there seems a distinct lack of German design input on the supersonic project, as both the M.52 & X-1 went with straight wings.
A bit odd on the face of it as Eric Brown was THE man who got hold of and tried all the German kit at the end of the war, including flying a live, rocket powered ME-163 ( other later, authorised flights were glide only for safety ) - and the Nazi supersonic wind tunnel was one of the things he found, though it or its' design may well have ended up in America.
Then again, judging by the DeHavilland DH108 swept wing job, which seems a jet powered approximation of the ME-163, and its' tendency to kill people as it wasn't quite right, maybe they realised they didn't have all the swept wing data...