Yes, you’re right. The theory blew me away at the time and seems to be gathering some steam with this new evidence.
I read a book on the explorer Percy Fawcett who disappeared into the jungle and was never seen again. The author tried to retrace his steps using some journals he got from his granddaughter or something like that. Anyway, he mentioned that the dense jungle was full of mounds which were remnants of pre-columbian settlements. All over. That observation supports the idea that the current rainforest region was densely populated and actively farmed centuries ago.