Now I have to wait and see if Apple will try and charge again today or if I have to wait. Very frustrating. I should have had my Apple Watch tomorrow, it seems, but this error may cause me to have to wait longer.
Unfortunately, the hold/decline was probably triggered automatically. An expensive piece of electronics being shipped to an address other than the billing address is going to trigger a red flag and at the very least get a second look.
It is a precaution against fraud but it can be frustrating and inconvenient when it triggers on a legitimate transaction. Hopefully you can get it cleared up without too much of a delay.