This is just marketing puffery. The defense would be "Microsoft was the first to implement ASLR and DEP on Windows, and Edge's sandboxing is the best sandboxing

This is just marketing puffery. The defense would be "Microsoft was the first to implement ASLR and DEP on Windows, and Edge's sandboxing is the best sandboxing technology available from any Microsoft browser product." Just like AT&T stating they have the "strongest" signal (which is a meaningless metric by itself), or car makers calling their car gets "40% better mileage!" and the * tells you "compared for a 1978 AMC Pacer."