On Arn’s podcast he says that as soon as they gave notice to the WWF, the Brainbusters immediately dropped the belts back to Demolition on WWF Superstars.  If they had stayed was it supposed to be pushed that all the way to WM VI?  And if so where would Andre’s
face turn have played in to that?

Also if they hadn’t given notice would Tully’s drug test failure been overlooked?

I don't think they would have gone for long with the Brainbusters as champions.  That one always felt like a short term deal.  And yeah, Tully's drug test definitely felt like a vindictive broadside by Vince, although in the long run it was probably better for him personally that he didn't get the WCW deal and was forced to clean up his life.  But it was definitely very suspicious timing that he just happened to fail a test for cocaine on the way out, in the same dressing room where RANDY SAVAGE and many others were presumably passing the tests.