Are the fish in the last area of Hades unobtainable after the credits?

The last part of the game changes after your reach the credits:

You stop getting to Persephone's farm and just get a cutscene before being thrown back to the house of Hades. But on the way to the farm, after the run completes, there are 2 lakes where you can fish.

Question is: If you do not get all the fishes that are available in those 2 lakes before the credits roll, are you then stuck that on that savefile, you will never be able to get those?

Solution 1:

The fish in those lakes are the same as the ones that can appear in the final Boss room as that's considered part of the Greece zone.

I've been able to get all 3 of the Greece fish from that room.