I'm not sure wouldn't someone say that it is bloating of such simple format as Markdown, but I really want to see embedding of TeX math formulas in Markdown RFC/standard.

I'm talking about $\frac 3 4$ and $$\int x dx$$ notation. It is already implemented in some Markdown parsers, such as Pandoc and Jupyter Notebook, but because it is not standardized there are also a lot of parsers that don't support it. I think that adding it to the RFC/standard would reduce friction in math communications and make them more accessible, especially if Markdown format become widely used for email communications.