What happens after 7 years of your IR test and you still have not got the ATPL unfrozen at that point but have kept the IR current?
Will you have to do ATPL theory again?
This is the confusion which is caused by using incorrect terminology.
You do not have an ATPL.
You have a CPL and an IR. You used ATPL theory as a credit for the issue of the CPL and IR. You have those licences and ratings, therefore only the renewal terms apply to keep them going.
Should you wish to get an ATPL issued, the theoretical examinations will only remain valid for ATPL issue or 7 years from the validity of the last IR. There is nothing to unfreeze, it is a completely new licence, with it's own issuing criteria, including passing a skills test as with any other licence issue. You wouldn't call a PPL(A) with CPL theory exams a frozen CPL, you wouldn't call someone who has passed the PPL(A) exams a frozen PPL, all the frozen terminology does is cause confusion over what people have, and what they want to apply for.
In the case quoted above, the 7 years only comes into play for the ATPL issue. It has no affect on the CPL or IR, as the theoretical exams would have been used in the relevant validity to issue both CPL and IR.