^^^he is right.
more complexity ::::> smaller probability of evolution
This is true only in the case of "evolution" from a purely materialistic origin.
A general understanding of statistical probabilities is sufficient for this "a priori" position.
Some evolutionists observe and report. . . . and theorize. . . . about how favorable events are "conserved" and propagated rapidly through multiple "applications" of successful strategies. That kind of thinking borders on ID. While denying an organizing intelligence or more specifically a "Creator" or "Designer" or "God", it acknowledges a fundamental trend in living things. . .. the capacity to act and respond in a way that favors "life". And diversity in life.
If you believe in a "God" or even "Cognition/Response" capacity inherent in "life", the probability of "evolution" is 1. Because "evolution" in that sense would be the certainty of an intelligent effort to propagate life by all possible means.