In order to correctly assess the consequences (not for the ex-minister, of course, but for the country), it is important to understand: is this a special case or the beginning of purges at the top?
It seems that there are no reasons for personal persecution of Serdyukov: he was almost from St. Petersburg, he belonged to the board, he did not betray his friends (his wife probably doesn’t count), and he did not betray his homeland. And dubious financial dealings here have never been a real reason for repression.