Gulf wild reef oysters are available year round. The non R months used to find the reefs
not harvested but short-time required refrigeration and mandated testing /HACCP certification of the oysters have it so that heat related vibrio vulnificus is not so much of an issue. LA & MS doesn't require oyster pasturization
If it's unshucked, then it's fresh, straight from a bed (reef) to you.
But with the char-grilled and baked oysters, sometimes their fresh shucked but most (horror of horrors!!) are actually IQF Half Shell Oysters. These are hand shucked with meat still attached to the shell and then put on a staging tray with their liquor poured over and then frozen and glazed. 12 to a tray. These can legally be called "fresh"and the biggest, peak harvest oysters.
Now the Horizon spill may change all this...........as beds 19 & 21 got closed today.