I agree OP, everyone is looking past Reyes, but he is legit. A live dog for sure. Oezdemir is a very powerful, competent striker, the fact that he was the one initiating the grappling exchanges should tell you all you need to know about Reyes's striking.
The biggest problem will be the clinch but I think he has the size, strength and footwork to avoid getting clinched. He has to exchange kicks with Jones and not let him be comfortable at distance, box him up, footwork will be key to finding angles. He has been working on his TDD, but a take down is inevitable, I think, when it happens, he has to keep calm and work his way up... easier said than done, just ask Gus.