Much easier to do while on AD than after a job change (regional, major, or any other job).
There is no sort of accountability for what happens to your financial situation AFTER the loan is issued, so nothing to worry about if the papertrail did not exist before the loan. Just because you might have been thinking about maybe leaving AD when you took the loan is irrelevant.
If you had a documented separation date when you qualified for a loan using AD payscale, and later defaulted on the loan it's hypothetically possible that there could be blowback regarding taking a loan under fraudulent circumstances. But that's pretty unlikely as far as I know, and as long as you don't default then it's moot.