Weird and mathematical presumably means that it is a floating point number.
You say that I have confirmation bias, but your confirmation bias is to the point where you cannot understand the plain meaning of the text.
But here is another quote for you: “Anyway, this leads me to matchmaking rating…All the system does when it comes to matching on skill is attempt to match you with people of a similar number.” – Jeff Kaplan Overwatch Forums
But if you want all the quotes, see How Competitive Skill Rating Works (Season 15), references section.