That’s exciting.
I’ve been to Teotihuacan and Tulum. Would enjoy seeing this discovery. I’d hoped to do a round-robin trip of the Yucatan peninsula and the scattered archeological sites there...but that’s not likely to happen without a Seal Team to accompany me.
I think you'd be ok in Belize. Touring Caracol was fascinating when I did it several years ago and there are other great Mayan sites in the country too.
Tikal in Guatemala, just over the border from Caracol, is a "don't miss" if the political situation is calm. When I was there guards with military weapons were posted at hotels and other places to protect Americans and other guests from being kidnapped and held for ransom. Seeing rough-looking guys with AKs hiding in the hotel landscaping was a little unsettling at first. As things currently stand I wouldn't go near Mexico.