I have seen this idea suggested before in the wider context of introducing spaced repetition systems, however, I think its a relatively small feature that can do a lot of good and should really be independent of other changes to the system.
The idea is to have the cards in each flashcards session shuffled (at least optionally), so that the student won’t be able to rely on the cards order to guess their meaning. This is standard practice in practically all other flashcards systems I know of.