No.

I do think Valve not being publicly traded allows them to be different in some ways such as the flat structure ("enshittification" as defined by Doctrow doesn't apply to Valve because there are no shareholders to please) but there's nothing "left" politically about Valve. Some of it I think is just not having to look good to shareholders allowing Valve to make actual good business decisions.

Valve's support of free software is because during the Windows 8 era Newell gained the fear that Microsoft would phase out Win32 in favor of UWP, cutting into Steam's business big-time. Microsoft definitely isn't going to pull that now that Windows Phone and the Start Screen concept both died and they've stated they no longer see UWP alone as the future, but I do think Valve administration still thinks it's best for their business to not rely on Microsoft's whims.