Twitter user @renka_schedule shared a number of tweets to that effect. After a rough translation, the patent basically point to the ability to play PS1, PS2 and PS3 games from the cloud. This is done via a virtual machine that emulates the operating systems of the respective consoles.

・PS1/PS2/PS3、様々な世代のゲーム機にわたる大量のゲームタイトルが、クラウドゲーミングライブラリを介して蓄積され利用可能。 ・これらのゲームは、それぞれのゲーム機に関連したオペレーティングシステムを模倣した仮想マシンの上で実行可能。 pic.twitter.com/TsWV859OLd — れんか (@Renka_schedule) July 4, 2020 But as NotebookCheck notes, these patents, despite being only recently published, date all the way back to 2012. In other words, these patents likely point toward the existing service called PS Now, rather than the PS5. Which is not exactly surprising, considering the mention of virtual machines via the cloud. That said, this doesn’t discount the possibility of the PS5 actually having backwards compatibility. The previous two patents mentioned earlier described the emulation of older systems’ OS as well as input language. But at the same time, as is usually the rule with patents, it’s best to not expect what is being described in them to be found without fail in the next generation console. (Source: @renka_schedule / Twitter, NotebookCheck)