An expensive question to answer at ~ $30/alt.
There's no guarantee. As long as they're not on the same bnet account, maybe. maybe.
There's just no particular guarantee that the fresh account won't inherit the flagged account status. Gold transfers and mail / alt moves are monitored, and AFAIK, there's still a person that has to trigger the ban if the automated systems have flagged something.
There's probably a benefit of the doubt on a new account, that is eroded by suspect behavior(s) early on, so, as long as you dither around and don't do anything for a few hours per alt, that account should be "good".
But that's supposition (a decent guess). We only really know how bliz works, when they do work to ban/flag/suspend accounts. And they do protect that process, because those mechanisms are singularly profitable for blizzard, and revealing them would prevent the income from players renewing accounts. It would also undermine the good will they bank on when removing players, if players were able to coach or troll players into making those mistakes and making the process much harder for bliz to use those triggers and traps.