Mathoid currently uses MathJax version 2 to convert the LaTeX dialect texvc to standard HTML ([nativeHTML](http://docs.mathjax.org/en/latest/output/mathml.html)) and [SVG](http://docs.mathjax.org/en/latest/output/svg.html) fallback images. Now, MathJax 3 dropped support standard HTML5, but introduced a new variant they call [common HTML](http://docs.mathjax.org/en/latest/options/output/chtml.html#chtml-options). However, it seems that the internal MathML representation is still available from the API.
If we updated to MathJax3 we lose the standard conform annotation of Math in the dom (even though one could argue that MathJax is the de-facto standard). It would, however,The update will improve the experience for most users, which is a very strong argument to update. I could not figure out if the new CHTML mode works without javascript enabled in the client. I think it should, but I could not find the information.