The rod bolt comes very colse to cam on straight rod MGB engines, that's why they are chamfered on the edges, when using a ARP rod bolt set on straight rod MGBs, you have to chamfer the bolt head yourself for clearence, as the bolt sold for MGB stright rod engines was originally designed for a AMC engine. Though even with stock MGB rod bolts it's really close,lots of things could cause this, a turned bearing in the past would cause the rod to move closer to the cam.
TO answer your question, no I wouldn't worry about it, as long as you have clearence now, you shold be OK, I even seen people put MGB cams on the lathe and turn them down between the lobe in these areas to give clearence.