Recently there's an influx of “PS5 backwards compatible” articles on google reporting it will play ps1 through ps4 titles. If it's true, much respect to Sony. : r/PS3
Is The PS5 Backwards Compatible?
Daily Reaction: Does PS5 Backwards Compatibility Matter?
PS5 and PS3 Backwards Compatible Update: Bug Gets Fans Excited - PlayStation LifeStyle
Backwards Compatibility - PlayStation 5 Wiki Guide - IGN
Exhaustive PS5 Backwards Compatibility Database Reveals Which Games to Play on Sony's Next-Gen System | Push Square