In JAA-land, 'frozen ATPL' is a term used by wannabes for simplicity and has no real definition.
Usually it refers to a CPL/IR with an ME Class Rating, passes in all ATPL exams, plus completion of an MCC course. The minimum necessary to have any chance of a first airline job.
You are correct in stating that, once employment has been secured, a TR and IR(MPA) follow - and after 500 hours of multi-pilot time, the licence can be upgraded to an ATPL.