Linked tickets can contain important or even essential information about processes, solutions, workflows ecc. related to a specific issue. However a linked ticket is too easily removed with a single (mis)click. Not even an explicit “Update” is required to permanently store the information in Zammad. To be on the safe side and to not loose links, you’d have to write the linked ticket number or link into a comment. This is redundant and should not be required.
I suggest to make the removal or change of an existing (ticket) link conditional/interactive through an appropriate dialogue (“Do you really want to remove the link to ticket ()”) to avoid unintentional removal.