https://www.dualshockers.com/ps5-backward-compatible-ps4/
Cerny also said that at the launch of the PS5 later this year, only a select number of PS4 games will be made available for play on the next-gen platform.
Cerny made clear that around 100 of the most popular games on the PS4 will be the first to be added to the PS5’s list of backward compatible titles.
It’s then safe to assume that more titles will then start being made available for play on the platform as time goes on.

PS5の互換はPS4のみPS1〜PS3は言及無し、PS5発売時には人気のある100タイトル程度のPS4タイトルが互換可能になる
その後、互換は増える可能性がある

ええ……