The tab doesn't hold the bearing in place, just locates it for installation. The rod/main bore is slightly smaller than the bearing and squeezes the bearing shells when torqued
Something to note: The bearings are held in place by the compressive forces applied when they're tightened. The notches (tangs) in the rod and bearing are just there to make installing them easier.
Everything made in cars should be heat resistant. You'd think in these day and age with advanced technology we would have created an engine that can't damage easily under severe conditions
