If Louisiana crawfish are like Oregon ones then the season is 365 days/year. I know they're farmed in Louisiana.
https://www.southernliving.com/seafood/crawfish/when-is-crawfish-season When you go to these Viet places, they usually say if its fresh or frozen crawfish.
I use to catch them all year long in Tryon creek in Oswego. My cousin dared me to eat one along with him so I did. I only ate the tail while he ate the tail and the thorax, Okay, I survived my dare and hope to never eat another. They taste okay, it's just the disgusting thought that got to me. Of course I've never had one with corn, potatoes and seasoning, just boiled in creek water in an empty coffee can. To me they were trash that just stole my bait when fishing for rainbow trout in the creek.
We used to go in the summers and had a spot in the Nehalem River outside of Vernonia where we got buckets of crawfish.
Portland city grill has one https://portlandcitygrill.com/menu.php?id=Brunch I remember back in the day going to the Benson for their Sunday brunch too. Saw its temp closed right now