Would it really? I haven't run across a device made in the last couple of years that doesn't support webgl. Allowing old technology to hold back new technology with a growing user base seems off.
Ehemmm....Canvas 2D is still supported more places & devices than WebGL than you think. I'll just tell you know, if Ashley does remove canvas2d support then anticipate the entire forum and bug section will be flooded like never before.
And who's to say that the new tech can't support things the old tech doesn't?
I'm just not following the train of thought that says "we can't do X because that would upset some people, even though not doing X holds everything back and upsets an increasingly larger number of people," but maybe I'm missing something?
Uhhhmmm.... Ashley is an entrepreneur, he thinks for the majority and as of now canvas2d is still needed by majority.
As a game developer, i would choose to make a game that is likely to be played by majority of players than those rarely are played by gamers by interest.