Your asserted that

Their only problem is with distributing the steam keys yourself for less.

Which is not true.

From the Bloomberg article:

Emails indicate Valve employees once threatened to delist all editions of Ubisoft’s Rainbow Six Siege “by end of day tomorrow” after they learned the publisher was marketing a separate $15 “starter pack” exclusively on its in-house Uplay store. In 2017, Kassidy Gerber, who works in business development at Valve, wrote to Warner Bros. executives that preorders for its new Middle-earth: Shadow of War game had been deleted from Steam because the price was “significantly higher than what was available at other retailers for the same version of the game.”

From the lawsuit itself, point 16:

Valve also requires game publishers to agree to give Valve veto power over their pricing in the Steam Store and across the market generally (the “Price Veto Provision”). Valve selectively enforces this provision to review pricing by game publishers on PC Desktop Games that have nothing to do with the Steam Gaming Platform at all. Through this conduct, prices set in the Steam Store serve as a benchmark that leads to inflated prices for virtually all PC Desktop Games.

English is hard, amirite?

This article describes allegedly that that is happening.

Of course these are “claims”. That point is made in the Eurogamer article, and the Bloomberg one, and the lawsuit. If your point is that whatever journalists write should be summarily dismissed unless there’s a final and binding judgement from a court of law, I don’t know what to tell you other than that is not how journalism works.