For sure - didn't think about adding the condition in the flow step!
I alternatively created a seperate Smart List that includes all "Currently Implied," with all the CA filters as well as the filter of "Opt-in Date in the past 6 months." Then, back on the daily campaign, if it's NOT in the Currently Implied group, it gets set to Opt-in = false, Marketing Suspended = True. I think both work, but yours is probably cleaner.