BMT ship date canceled

Looking for some advice. I had a BMT date scheduled and was supposed to ship out this April. Recently, I got a call from the DTF Program Coordinator saying my BMT date has been canceled because I’m no longer eligible for the job I originally booked. The job requires a security clearance, and they said citizenship during BMT is no longer allowed. I’m a green card holder, and I had already completed my security clearance background investigation. I’m a bit confused about what this means for my enlistment.