Not quite "Nuff said"
They've advertised recently for F/O slots on the freighter with "rapid command". If you joined the company today with a shed load of experience on the Classic and took a couple of brave pills you could probably start an F/O course and switch it to a command course if everything was going OK. The seniority for command on the Classic is zero so as soon as they're willing to give you a go you could find yourself doing a course.
There are many reasons why I wouldn't recommend this course of action, do a search on this forum under classic or freighter and I'm sure you'll find them!
Good luck