What about it is misinformation? It's practically just Steam's own announcement worded differently. Everything in it is verifiable and supported by the Steam blog post.
First off it's confusing as hell where they try to paraphrase or summarize for what Valve already said plainly if you bypass this blogspam article and just go to their support page where they spell everything out neatly that any 32-bit games will remain in your library and accessible, albeit that your OS may not place nice. This article almost makes it as if they're removing stuff from your library, which Valve clearly says they're not doing. The summary AI bot would do a better job sourcing the Valve blog update than this writer did.
This article almost makes it as if they're removing stuff from your library
But it doesn't remotely imply that? Here are the words/phrases it uses to describe what will happen:
Steam will halt support for macOS 10.13 and 10.14
existing Steam Client installations on those operating systems will no longer receive updates of any kind, including security updates
some games will effectively stop functioning on macOS
The Steam store will stop considering games that offer only 32-bit macOS binaries to be Mac compatible at the end of 2023.
At no point does it say or imply that anything will be removed from your library. In fact, it explicitly says how you can ensure that those games you own will remain playable:
In order to ensure continued operation of Steam and new 64-bit games purchased through Steam, users on these older versions should update to a more recent version of macOS.
Why would they include that if they're trying to tell people the games will be removed from their library?
Is it possible you might be looking at this old support page from when MacOS first dropped support for 32 bit apps but Valve was still supporting the 32-bit client for older MacOS versions? The current page is this one. I doubt they'll be removing games from your libraries at any point, but the new article makes it clear that they aren't supporting the 32-bit Mojave Steam client or 32-bit games on Mac anymore and make no guarantees that they'll continue to work when the client stops getting updates.
After February 15th, 2024, we will no longer support macOS 10.14 or earlier and we are unable to guarantee continued functionality of 32-bit macOS games after that date.