The 500W is an estimate for the next generation CPUs so we have to speculate, but yes the performance per watt should make sense unless those products are awful

The 500W is an estimate for the next generation CPUs so we have to speculate, but yes the performance per watt should make sense unless those products are awful. Thus far every EPYC generation has been substantially better performance/watt but the top-end power draw has gone up because the number of cores has gone up. EPYC 3 (Milan) maxed out at 64 cores but EPYC 4 maxes out at 96 (Genoa Zen4) or 128 (Bergamo Zen4c). So you get twice as many cores, faster cores, and much less than twice the max power draw (~240W > ~360W). The highest core count CPUs tend to be the most efficient as well because you amortize the relatively static power draw of the IO-die (and the other parts on the motherboard) and because they tend to have lower more efficient clock frequencies. It's pretty safe to assume the situation will be the same with next generation EPYC 5 CPUs with maybe 192 or 256 cores, higher power draw, but more efficiency.