If it doesn't now, it never will have official Dell support -- and since the only way to have official support for Linux is to purchase the system with it, it really doesn't matter anyway. It may run Linux just fine - but you're on your own if you decide to install it.  
Dell Vostro 3070 supports Ubuntu: [URL] Dell official website not listed Ubuntu for Dell Vostro 3070   Is my brand new Dell Inspiron 14 7420 2-in-1 going to supports Ubuntu soon?
Ubuntu in the future?