I do not think they did, not sure what "in lifts mean". With it being the end of the season in NJ the decking may not be poured until spring. I am meeting with the concrete guy next week to discuss.
Compacting in lift means they should have installed one foot of material then compacted it with a heavy compactor (preferably a sheep's foot compactor for clay) then they would install the next one foot lift and compact that. so if you had 4 ft to fill they should have compacted four times.
dumping loose material in a 4-ft fill and then letting it sit for the winter does not achieve the proper compaction.
Does this concrete guy work for the pool builder? If not ask him about placing his concrete on 4 ft of uncompacted material.
Unfortunately, improper compaction seems to be the standard operating procedure of most pool builders. It usually takes years to settle and move your patio and by then they are long gone.