The only criticism I see is some nitpicking saying that the claim “was based on statistical means, ignoring the known intense drops in the energy expenditure that some individuals show during their life. For example, a clear decrease in metabolic rate is observed in humans that consume calorie-restricted diets (Fothergill et al. 2016), an adaptation named ‘metabolic slowing’ (Johannsen et al. 2012). Therefore, the statement is innacurate and possibly wrong.”

These critics don’t seem to disagree with the core claim about average metabolism across the lifespan.