https://videocardz.com/newz/microsoft-pc-game-pass-is-coming-to-nvidia-geforce-now-later-this-year
 
Select games from the PC Game Pass library, possibly including some EA Play titles, will be available through the NVIDIA streaming service, Microsoft announced today. This should extend the support for many new devices at no extra cost for short sessions because the NVIDIA game streaming service is available in a free 1-hour tier. Those who prefer longer gaming sessions and higher quality streaming, may consider upgrading to the new RTX 4080 tier.
 
The GeForce NOW service works on PC, Macs, Chromebooks and TVs, not to mention Android-based setup boxes, tablets, and smartphones. Turning those devices into remote PC game streaming device may soon only require a good Internet connection and a keyboard/mouse or a game pad.

Today we shared that Game Pass members will soon be able to stream select PC games from the library through Nvidia GeForce NOW. This will enable the PC Game Pass catalog to be played on any device that GeForce NOW streams to, like low spec PCs, Macs, Chromebooks, mobile devices, TVs, and more, and we’ll be rolling this out in the months ahead. We’re excited by our future – to grow the industry, bring great new first-party titles every year, give partners more ways to deliver and access games and offer multiple ways to play all of them, wherever our players want to play. We are looking forward to going on this journey together with our community.
— Microsoft

Worth noting that Microsoft only says that ‘select’ games will be available, not the full library that features over 100 games. According to the post, GeForce NOW support will be unlocked in the coming months, but neither Microsoft nor NVIDIA have confirmed the exact launch date.
 
While it is true that only 'select' games will be available this is a way for GeForce NOW to expand its library.