need advice on animal damaged kwanzan

hi, firstly thank you to anyone who can offer advice. full view of the tree as i left it last night is in the last slide.

about a year ago my girlfriend and i planted a young kwanzan cherry tree, and it seemed to be doing fine throughout the winter. however, when we went to visit it yesterday, we discovered that an animal had seemingly chewed a ring around it near the base of the tree, and there is very little bark left in that region. you can see a close up of the damage in the 1st and 2nd photos, its like that around the circumference. there is new growth and little buds coming out from each of the branches which leads me to believe this injury happened very recently.

obviously this is the kind of thing that can kill a tree, so in a panic, we tried to find advice online on what to do. it seemed like what the internet agreed we had to do was take wet sphagnum moss, pack it around the injured bark, and then wrap it in plastic wrap and tape it up. we already had sphagnum moss so we did just that, as you can see in the 3rd photo. we then built a little metal grating fence around the tree and covered the top of the fence in mesh so animals couldn't get in from above. you can see this in the last slide (the mesh hadn't been affixed yet in that photo).

i spoke to my arborist friend and he suggested that i remove the moss and wrap because it can cause rot. he suggested i leave it bare and apply a rodent guard, and said keeping anything above the root collar consistently moist was usually bad for a tree.

however, today i spoke with the nursery where we purchased the young tree a year ago and they said to do the sphagnum moss thing before i even revealed i had done just that. they said to leave the wrapping on it "for a long time", and they also suggested i add root hormone into the moss if i hadn't already wrapped it up.

anyways, now i'm not sure what to do as i have conflicting advice, and i don't know whether i should be removing the wrapping we made or leaving it. my girlfriend has been wondering if we should do something like affix some sort of soil container to the region, like a makeshift pot, but i don't know if something like that would be good for the tree. since this happened so recently i'm trying to make the right call asap.

any advice would be greatly appreciated. i know the tree is sadly in a very dire state and may not survive, but this tree has high sentimental value and i want to give it the best fighting chance despite its unlucky circumstance.

thank you again for the help.