IRS DRT will be back for 2018-2019 ... with some changes

By itself, the update should not have led to you being selected for verification. Most likely, had there been no rollover & using just your other information, you would have been selected the first time around. With the higher EFC from the rollover amount, you were out of range for the selection formula to bother with you. When the fix was applied, your EFC dropped enough that the selection formula picked you.