Continued Beni civilization?

So I'm reading 1491 again and thinking about the Indians of the Bolivian Beni savanah. These people built impressive canals, causeways, and weirs but apparently disappeared in 1450, over two centuries before the isolated region was reached by Europeans. Unfortunately they lived in a tropical region and very little artifact survives.

What if their society somehow kept going for a few centuries longer, would they have any chance of surviving into the modern age.
 
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