I think gov will still give to prisoners and safe keep for them until their release without expiry date. For those life imprisonment ones probably gov will ask them to nominate someone to use the voucher to buy things for them during the visits.
For imh patient, gov will still give them although they cannot go out to use.
Is same like some siao lang that are not locked in imh. Gov still give them but they might not know how to use it and that's not the business of gov.