Ultimately the reviewer should be paid for their efforts because honest reviews are their livelihood. Saying, “I liked this and if my review helped, buy through this link to support me for free,” is a fairly innocuous way.
Is it completely unproblematic? No, but earning money for your opinion is always going to be fraught.
I’m excited to hear this. I thought DW was everything I enjoy about fantasy roleplaying without any of the bullshit. I’m not familiar with Burning Wheel or Luke Crane, but I’ll look forward to seeing what he comes up with.