I'm sorry I can't confirm this (I can't get your ant script to work on my system), but it looks like your packages/deft/test/karma/touch/2.3.0.conf.js file was copied from 2.2.1 without changing the coverage directory, which I'm guessing overwrites the 2.2.1 coverage report:
coverageReporter: {
type: 'html',
dir: 'test/coverage/touch/2.2.1'
},