I'll wager this will never be implemented, as its detection would be much more hassle than the feature it would provide.
However, there is a cure. Simply do this when yelling:
//say $upper(yelling goes here)
Type that and when you get to their name, type it partially, tab, and then when completed, hit enter. As long as everything is inside of the $upper() identifier, it will say everything in all capitals.
//say $upper(zmodem you are so terrible!)
ZMODEM YOU ARE SO TERRIBLE!