Ability to prevent withdrawal using additional phrases or user generated password which user can opt in and out from.
For an example; when a wallet is generated a pass code is given to the user. User can then opt-in for withdrawal lock and an additional phrases will display. 2 years down the line in a different phone the user must have both set of phrases; one for linking the wallet back into their new phone trust wallet app and a additional one if the user wishes to opt-out from withdrawal lock inorder to transfer their token they have been hodling.
This way the wallet can stay decentralised, no user data is required and the additional security is bined to the wallet itself.