Got a contract-to-hire offer and can't tell if 'we'll figure out the conversion after 6 months' is normal or a red flag

Three weeks into a 'contract-to-hire' role and asked my manager what the actual conversion criteria are. Got 'we'll figure it out around month six' as the answer, which either means it's genuinely informal here or nobody's decided if the headcount exists yet. Still doing full-time work and going to standups like a permanent employee. Anyone had this actually convert into something concrete, or is vague-conversion language usually a sign to keep interviewing on the side?