Well, the old JAR rules were defined in FCL 2.495. And they practically remained the same in EASA Part FCL. From JAR FCL2 Amdt 3:
JAR–FCL 2.495 Acceptance period
(a) A pass in the theoretical knowledge examinations given in accordance with JAR–FCL 2.490 will be accepted for the grant of the CPL(H) or IR(H) during the 36 months from the date of [ ] gaining a Pass [ ] in [all] the required examination [papers].
(b) Provided that an IR(H) is obtained in accordance with (a) above, a pass in the ATPL(H) [theoretical] knowledge examination will remain valid for a period of 7 years from the last validity date of the IR(H) entered in the CPL(H) for the issuance of an ATPL(H).
(c) A pass in the ATPL(H) theoretical knowledge examination will remain valid for a
period of 7 years from the last validity date of a type rating entered in a F/E licence.
So if you passed the ATPL/IR theory and did obtain an IR(H) (-> para b),then the ATPL/IR theory expires 7 years after your IR rating expiry date. If you did not obtain an IR(H) (->para c), then your IR theory expires after 36 months (-> para a) and your ATPL (VFR, that is) theory credits expire 7 years after your type rating expiry date.
Since the original scenario was without IR(H), I still maintain that the ATPL theory practically doesn't expire as long as you have a type rating.