This 2010 letter by Bill Parsons, then-Acting Director of OSHA’s Directorate of Construction, says that you can’t bevel with the side of a saw blade unless the blade is designed for it. That’s because beveling is considered to be “side-grinding” – that is, cutting perpendicular to the blade’s cutting edge – which is covered under ANSI B7.1-1970: “9.9 Side Grinding. Side grinding shall only be performed with wheels designed for this purpose.”
That’s the legal reason why you shouldn’t bevel pipe ends with abrasive and welded blades.
The practical reason is because beveling can break these kinds of blades. Neither kind of blade is designed for the lateral pressures of beveling or side-grinding. These pressures can shatter abrasives and break the welds holding the cutting segments on welded blades, creating shrapnel that can injure or kill the saw operator.
However, you can still bevel pipe with your saw blade. You just need “wheels designed for this purpose”, like Ductile Iron Safety Blades. It doesn’t matter whether you use Ductile Iron Safety Blades for cutting or beveling because they’re made of solid steel, so they won’t break or shatter.