If the claim was that Bill Gates wanted to make viruses for Windows so that people buy his anti-virus software, the it does matter how it's bundled.

Since Windows Defender is free, he's not making any extra money because of its existence. He has no incentive to create viruses.

And as I said previously, Windows Defender was part of Windows Vista and onward, which was after Bill Gates stepped down. All their recent services like Azure and Endpoint protection are also after Bill Gates stepped down.

I don't like Microsoft, I think most of their products are junk, and I'd be just fine if someone were to execute Bill Gates. However, I'm not going to claim he had a financial incentive to create computer viruses, when the evidence for such is sorely lacking.

If anyone had a financial incentive to create viruses back in the day, it would have been Norton/Symantec and Mcafee, the two leading companies that built their fortunes on their paid/subscription anti-virus services.