Keep in mind these are all rumours, I have no inside info unlike others on this forum.
An option for more Kitchener service (to Kitchener) in the immediate term is on weekends. Zero trains run now so adding up to 5-6 per day is possible with existing infrastructure. In the near term, new passing tracks at Guelph GO and Breslau will help increase frequency, but not get it to hourly. Future projects will enable that.
Route 30 from Bramalea is the fastest GO bus route to Kitchener-Waterloo, and a better connection from Toronto and York Region than Square One, especially with the new Bramalea Station configuration. Even weekend rail service to Mount Pleasant and regular Route 30 connections would be a big improvement.