It does happen more often
It does happen more often than you'd think that the coolant causes the piston to break. I have one in my shop now that broke the piston then the rod punched out the block front and back. You can look straight through the engine.
Once that morning miss begins I wouldn't waste time getting the gasket replaced along with cleaning out the EGR heat exchange. I,ve gotten to where it's better for me to keep a few cleaned EGR coolers on hand and just exchange them when doing the head gasket job or....replacing the engine.