I Didn't know where this question should go. Chrome has ended support for some plugins and now does not render LaTeX using MathJax well (for example the fonts don't look right and there is a vertical bar following the math expressions in Chrome). Firefox is ending support by end of 2016. Is this going to be a problem or is this transition already solved? I don't know the details of the plugin interface html5 etc. to know whether the transition is a problem or not? But judging from what is happening in Chrome, it seems like it could be a problem.
MathJax is not a browser plugin, so changes to plugin architecture and policies do not affect it. MathJax is written in javascript, and support for that is critical for the functionality of most modern websites, so it is unlikely that MathJax will stop functioning in the future. The issue with the vertical bar in Chrome is due to a change in how they interpret very small dimensions (aka, a "bug"). MathJax 2.6.0 (released at the end of 2014) works around that issue. I'm not sure what you mean by "the fonts don't look right", so I can't comment on that. But you can rest assured that we see no reason why MathJax will not continue to work into the future.
Thank you for those assurances and clarification. I was under some vague impression that java was being deprecated and people were supposed to move to html5 or something like that. I do want to invest more heavily (time) in WebWork and want it to continue working well into the future.