Hi Dan,
I'm not sure you'd need to pause them but you could push them through a decision rule that looks for an account id and rechecks for a time period (whatever you know will allow your CRM synch to properly run and push the account info back to all the contacts), then if they do not have an account ID the no path can restart them in your process (essentially creating a loop) and the yes path can push them forward.
Best,
Lauren
