If it were indeed “fact” it would be documented and substianted yet I haven’t been able to find any substantiation other than one case: the infamous blowup from a super high pressure handload. I’ve seen correspondence from Blaser pertaining to this and it’s the only case I know about or Blaser mentions. Blaser was quick to react to the rusty parts/inadvertent firing issue, so I lean towards giving them the benefit of the doubt vs internet scuttlebutt.
You are correct the R8 replaced the R93 for the most part. If I’m not mistaken, R93 production halted in late 2017. If there was a problem, I’d like to think Blaser would’ve stopped production a whole lot sooner. The R8 is better suited to larger chamberings/calibers (hence its redesign from what I gather) but it also weighs a fair bit more.
Doesn’t matter since you’re not interested in it, but it has been an interesting conversation.
CB