Non backwards compatibility with previous versions of windows mobile?

i don’t know whether this is true or not but if so this really sucks. its hard for me to believe that Microsoft would make a new OS that’s not backwards compatible, to me that seems counter-intuitive to the end goal. There are a countless number of WM 6.x apps (not 2 mention previous vers as well) prob way more than any other mobile OS and to just cut all those great programs (most of the greats made by the brilliant programmers right here on this site) out would be a foolish mistake.