Valve no longer supports Source 2007 Dedicated Server (SRCDS) on Linux because they have phased out older master server support for legacy versions of their engines. They focus on Source 2013 and later versions, as well as their proprietary matchmaking systems (Steam Networking, VAC, etc.). The master server shutdown means that servers running Source 2007 cannot be listed publicly without third-party solutions.
Why is ReHLDS and Other Cracks Tolerated?

ReHLDS and similar projects modify GoldSrc engine servers (e.g., Counter-Strike 1.6), often claiming performance and security improvements. While they are not officially endorsed by Valve, they remain widely used because Valve has not taken action against them, possibly due to the continued popularity of CS 1.6 in certain regions.
Are There Legal Alternatives for Source 2007 Mods?

Yes. Mods like CS ProMod (SDK 2007) and upcoming projects like CS Legacy (SDK 2013) use official SDK files provided by Valve. These allow for a legitimate transition from GoldSrc to Source, without relying on pirated software. However, Valve does not actively maintain SDK 2007 anymore, making SDK 2013 the recommended choice.
What Can You Do?

If you want a working master server list, you might need to migrate to Source 2013 or use third-party listing solutions.

If you develop mods, SDK 2013 is the best option, as it is still somewhat maintained.

If you run a dedicated server for an old Source 2007 mod, you will likely need workarounds to ensure players can connect (such as direct IP connections).

P.S. GPT chat ;)

I am up to date with everything written here. It was about cspromod. Cs legay is in progress, so it's out of the question for the moment. This is not my first post on this topic. I am waiting for a response from a valve official. On scrds 2007 windows the master server works, on linux it does not. Even if I put sv_lan 1 in the start line, the server will appear in favorites without any problems including on gametracker, but it is not listed in the master server,
what do you mean by "third-party listing solutions"?

I see, you're already familiar with the general situation, and you're specifically asking about why SRCDS 2007 Windows still works with the master server, while Linux does not. That does suggest an intentional or unintentional deprecation of the Linux version by Valve. If you're waiting for an official response from Valve, your best bet is probably the Steam Community forums or contacting Valve through a support ticket (though they rarely reply to such issues).
About "Third-Party Listing Solutions"

By that, I mean alternative ways to make your server discoverable despite the lack of official master server support. Here are some options:

Direct IP Connection (Manual Favorites List)

Since your server appears in favorites and GameTracker, you can distribute the IP address manually.

Players can add your server to Steam’s "Favorites" list in the server browser.

Community Master Server Lists

Some projects maintain alternative master servers that work similarly to Valve's original system.

Example: SteamMasterServer (SMS) allows older SRCDS-based games to still function.

Some server hosting communities offer custom "master server" patches that redirect clients to a maintained list.

GameTracker & Similar Services

Websites like GameTracker.com can still track and list servers even if they don’t appear in the in-game browser.

While this doesn’t replace the master server, it helps players find your server.

DNS-Based Workarounds

Some server admins use DNS tricks to redirect server queries to alternative master servers.

This is more technical but can be an option if there’s enough community interest.

P.S.S.
your beloved GPT chat