For Basel modellers, a common problem is a relatively short period of data. In most firms, they might not even able to get up to 5 years worth of data. Hence, the PD models would normally reflecting a Point in time (PIT) estimate or a Short run cycle (SRC) estimate.
Now, its nothing wrong having a PIT estimate. It is really up to the Bank’s senior management to decide if they want: –> You can read more here