I think by AMD's new lineup they're referring to Ryzen 3000 series, which isn't out yet. If the rumors are true, the top models come with 12 to 16 cores, higher IPC and higher clocks than the current Zens, pushing 5GHz boost.
A current 9900K might be some 20%-30% faster than a current Zen, but it will no longer be so when with the new lineup.
Meanwhile mitigations are eating up Intel's performance advantage..