So, if your flight was changed to a MAX, would you fly on it?
Kind of like the software that most banks run on. It's critical infrastructure that is largely composed of cobbled together COBOL and Perl scripts. You really don't want to break them open and see what's inside, but they have evolved to be stable and correctly take their inputs and produce the right outputs.
I'll try to avoid if I can for a while longer, but I think this will work itself out.