The problem with adding this new syntax stuff is halting the seasoned Python programmer in their tracks when they see := and trying to Google what the hell it is. A half day later, they finally find something describing this as a new walrus operator that, oh by the way, returns a value without implicitly calling any function. At this point, she mutters "shit - lost half a day on this crap" while her manager steams in being told she can't make today's deliverable anymore.  IOW - this new bauble is going to waste uncountable time to multitudes of developers.