The only reasons I can see for it not working would be: 1. predictions that AGIs will come before the next generation of rationalists comes along. (which is also a question of how early to start such an education program). 2. belief that our current researchers are up to the challenge. (even then, having lots of people who've had a structured education designed to produce the best FAI researchers would undeniably reduce existential risk. no?)

I can't speak for the SIAI, but to me this sounds like a suboptimal use of resources, and bad PR. It trips my "this would sound cultish to the average person" buzzer. Starting a school that claimed it "emphasized critical thinking" to teach rationalists might be a good idea for someone with administrative talents who wanted to work on x-risk, but I can't see SIAI doing it.