One could argue there's a difference between replacing the snorkus and removing the snorkus. The former implies replacement with a straighter flowing piece. The latter implies a gap between air box and side-of-fender, which can suck in hot engine-compartment air, and the flapping of the rubber gasket can cause turbulence, possibly around the MAF. Enough to cause running lean? That I can't say.

In terms of that quoted "story", I would argue its all a FUD attempt (Translation for Franklin: spreading Fear, Uncertainty, Doubt about something). Notice he doesn't say what the mod levels of these blown-motor cars were.