Yes, wash trading should be assumed to be ubiquitous in the NFT space. It's too cheap and easy to create fake trades of NFTs to trust that transactions are all real.

The tokens described in this article don't necessarily depend on the sale price of the NFT, though. Instead, these NFTs would represent the beneficiary of real-world contracts. Whoever holds the NFT collects the future income of the person, as enforced by a real-world contract.

Of course, nothing stops them from wash trading these NFTs in an attempt to flip them.

At the end of a day it's still a token, so all the usual scams (eg. pump & dump) still apply.