I think for most English speakers, “Mortadella Bologna” and “Bologna sausage” are separate things, with the latter being like a completely homogenous tube of meat slop, and anything that has actual bits and chunks of stuff separated inside of it getting called “Mortadella”.
Mortadella was banned for import to the US from the 1960’s to early 00’s, so there isn’t a very large cultural footprint here for it. Americans might (incorrectly) call it a “Summer Sausage” if not just think of it as gross bologna (they prefer the fat content of their cured meats to be obfuscated by the meat obelisk.)