I spent two vaults on the new crates (yeah) and got 51 items. Given 10% rare and 20% uncommon, I'd expect to see about 5 rare and 10 uncommon items on average. Instead I got seven uncommons and only one (!) rare.
Obviously that doesn't mean there's a bug somewhere - if a hundred people buy crates with vaults you'd expect someone to get such outcomes - but I'd hold off on buying the new crates till more people report "normal" behavior.