There’s all kinds of stuff flying around the internet & its hard to know whom to trust or the basis for various claims.
Here is one widely respected website for all things & questions oil: http://www.bobistheoilguy.com/cms/
I would also just echo the previous comments. I don’t find the story plausible. That said, there are often multiple viscosity recommendations that largely depend on air temp. So I have 2 cars where the standard recommendation is 5w-30. But when you look closer it also says 10w-30 is fine if the temps remain above zero. Don’t forget to take your own climate into account as you think about this.