Hi Heather,
Since Marketo is only looking at individuals, it won't take out the entire Account.
It might be possible to do something more complex, (and I just realized you left Marketo, congrats on the new role!). Maybe something like:
Smart List 1: pull contacts
Smart List 2: take Account Names from Smart List 1
Flow: then Block (or whatever).
But I think you'd have to do some fancy thing with the API or pull the Account Names and then add them back manually using a different smart list and flow step.