USM isn't even to issue 5 yet. If it's still selling like that at 20 or 24 that's an entirely different beast. For now, one imagines that Marvel is just thrilled to have two Spider-Man books that are top sellers in the market.
As much as I loathe everything Wells has done with Spider-Man, his book sells. Hickman selling more just means they have two huge titles. USM succeeding isn't going to impact ASM. ASM would have to tank to bring about that eventuality.