Only a disaster last 20 years. That's when populations began to decline in many parts of TN.
But the decline is multifactorial. 4 bird limit, more turkey hunters, more effective killing techniques all cause a larger percentage of adult males to be removed from the population and leaving fewer or no birds left to fertilize hens in June.
Hens initiating nests at lower rates than before, fewer eggs hatching, fewer poults surviving is causing the population to decline.
From a selfish standpoint (because I love calling turkeys to me), I much prefer the mid April to Memorial Day weekend season. Unpressured birds in mid April are just SO much easier to call in than henned up birds end of March. And I LOVE being able to hunt Memorial Day weekend. No need to head out west or up north to prolong the days I get to spend afield.