Bragging about how product is at doing something is the easiest way to advertise product. No conspiracy theories needed.

They want you to use their LLM to screen your code for bugs. When you do that, you see how surprisingly well it works now and that leads to you wanting to also use it for generating code. That is when you realize that the 20 bucks starter subscription isn't enough to actually use it professionally... which means, you upgrade and they get moar money.

Didn't they use LLMs to code Win11 though?

I've said this a million times. The llms are not better, than us they are infinatly faster. It's like putting 1000 engineers full time on looking for vulnerabilities for 10 years. Sure you can do that. Or pay for the tokens instead and do the same effort overnight.