In case anyone searches this, the answer is "After 90 days the temple would check with the stake president. If he approves, no need to issue a new recommend."
For clarity, who provided this answer? Did it come from your local temple, or from another source?
And anyone finding this thread, could also reference this Forum post which talks about the
Shelf Life for a non-activated recommend, which seems to have the same general conclusion as what you were told: nothing totally official, but 90 days does seem to be a trigger point for additional consideration for both living ordinance and standard recommends.