Yea, their instructions change all the time. A professor with LSUAG gave me the no fertilizer advice. He said compost or some other very low nutrient combination will work. Same thing with the Pecan nursery where I bought my pecan trees. Dig a hole two to three times the size of the root ball or container, break up the dirt removed from the hole, combine with enough well cured compost to slightly loosen, then backfill. Mulch well to retain moisture and retard the weeds but do not fertilize the first summer.
That's why I am so interested in seeing how your trees do this summer. I want to try and find out which instructions are the best. My peach trees are 8 years old now and I need to be prepared to start replanting winter after next.