If you have a grade 4 lesion, then the cartilage and/or bone has totally broken away. An xray only takes a flat picture so it could have appeared like a bone spur on an xray perhaps. But, when the got to the MRI, they were able to tell better what it was. This is only a guess from me. I was never told I had a bone spur.
When is your surgery?
Sorry about Disney not being magical. My family previously went to Disney several times a year. Last year we didn't go after I fell. I am looking forward to going back this year, though.
Good luck with your journey to being healthy again! I would suggest finding the absolute BEST foot/ankle surgeon that you can.