I have heard that that discharge on those grounds can lead to forfeiture of all pension rights, gratuities and resettlement package,
As politely as it can be said....not correct.
An admin discharge carries the same status as a PVR. All minor and most major formal charges as well as all admin discharges (for whatever reason) are treated as admin discharges for the sake of pensions/resettlement packages etc.
To lose the lot as you suggest you have to commit one of the biggies...murder, high treason, somthing of that ilk.
Moreover, I do not think this is something it is within the remit of the military or the government to change without primary legislation, because all military punishment tariffs have to reflect their civilian counterparts as required by UK law.