My DD10 and DS8 love their "toast" only slightly warmer and dry(er) to the touch than an untoasted piece of bread in the toaster, and think that when the toast turns any shade of brown it is burned (I know...they are weird).
DD LOVES peanut butter and eats it on her "toast" every day. Lots of it. Probably as much as one packet of PB that is put out at food courts or buffets. Sometimes, if she is exceptionally hungry, she will even go as far as toasting TWO pieces of bread, spreading PB on both, or even one side with PB and one with jelly, then smushing the two together and eating it like that!
If she wanted that at WDW and there was PB packets out, like there are at many food courts, breakfast buffets, or 2-star hotel breakfast rooms (Mmmm - waffles!), I sure hope none of you are around to see this - I'd be afraid the "sandwich" would be ripped out of her little hands and we'd be stuck with a lecture fro the food court PB police on the indecency of not using the peanut butter for its intended purposes!!!
If you buy the bread, it doesn't matter how you toast it, when you eat it, or how you prepare it. Slather PB, jelly, or butter, or mayo. Who cares? You bought the bread, you get your choice of condiment to put on it. 1 slice of bread=one condiment.
Let it go people.
ETA: And FYI - The only reason it would be discouraged is because it makes you more full - thereby not being hungry enough to feel the need to purchase a $8 hot dog two hours later. But even seeing this through the eyes of a money-hungry business doesn't make it morally wrong for a person to use a complimentary condiment on a relevant food item that was purchased at the same place the condiment is offered. and, I am sure the parks would be THRILLED to see a mom making her little one a "bread and peanut butter" sandwich with bread and PB packets put out at the buffets...imagine all of the savings on the cost of bacon! It's amazing how that suddenly could work in favor FOR the business, isn't it??!!