I've found a few morels in may apples over the years, but I think that it is incidental to the morels location, not determinative. I love all the lore surrounding mushroom hunting, my father-in-law always used "when the lilac leaves are the size of a squirrel's ears, the mushrooms are up." His woods were always a good mushroom hunting spot, and occasionally a GREAT spot!
Just to turn the crank, so to speak, here's a picture of the largest morel I've seen. Found in the early 2000's by my cousin.
Morels in particular are one thing my property has always struggled with. When I was a kid I was real good at finding them with my grand father......I would tend to step on several in the process of finding one. He would get so frustrated! How he didn't leave me in the woods sometimes I'll never know! I finally got demoted to holding the onion sack and walking BEHIND him!