As noted in the article, it is known that Zen 5 is a new microarchitecture, not just one with small incremental changes, like Zen 4 over Zen 3. Therefore it is

As noted in the article, it is known that Zen 5 is a new microarchitecture, not just one with small incremental changes, like Zen 4 over Zen 3. Therefore it is expected that the performance increase at the same clock frequency will be substantial, at least 20% to 25% on average. It is also expected that some applications will be accelerated much more than the average. Usually SPEC has a performance increase not too different from the average, so 40% seems high, but not impossible, because the IPC would remain lower than for the Apple CPUs. By the end of the year, both AMD with Zen 5 and Intel with Arrow Lake and Lunar Lake are expected to introduce new microarchitectures, after several years with only minor microarchitecture improvements in Zen 3/Zen 4 and Alder Lake/Raptor Lake/Raptor Lake Refresh/Meteor Lake. Hopefully both will demonstrate good advancements over the current CPUs.