I guess it would be like Bill Gates advertising for Windows and Xbox at the Bill and Melinda Gates foundation. Like I get the incentive but it doesn’t seem like the right place for it
To be clear I think the weirdnesses is in the pseudo-personal tone of it. This isn’t your uncle trying to sell you on his new business during thanksgiving dinner.
This is a billionaire trying to sell low low prices to presumably investors.
Or like Google's home page advertising Chrome (which they did early on in its life, which was surely a big factor in how they grew their market share so fast).