Can't really tell by the picture but if I paid for a new, healthy tree, I wouldn't accept one that looked like that.

Looks like the wound might have been spray-painted or something? Just sayin, but that tree's root-flair is way too deep (or way too much mulch).

I agree.

Your tree is what they call 'Telephone poled' where there the trunk goes straight into the ground with no sign of the root flare.

This alone can cause the tree to develop problems. Even ones like you show in your picture.

Bark is not intended to be below ground in the dirt. Better to be a little shallow with the planting then the other way around.

See diagram below: