While I have not had a need to delete a term and reuse its SIS ID, before I delete a Canvas course I change the course's SIS ID and integration ID before I "delete" it. I would recommend doing similar steps for anything that has an SIS ID (or integration ID) before deleting (or as I describe below, moving) it.

Technically I move the Canvas course to a "Trash" sub-account and "Trash" term) so that I can (potentially) (a) reuse the (because of standardization for how they are formatted) SIS ID or (b) do not have to restore the course if there was any content in it.