Does he think all the properties of superintelligent systems that will be relevant for the success of alignment strategies already exist in current systems? That they will exist in systems within the next 4 years? (If not, aren't there extremely important limitations to our ability to empirically test the strategies and figure out if they are likely to work?)

I think Asimov’s Foundation is a great example of this! It features the establishment of a space colony with the goal of drastically reducing the length of an age of galactic barbarism, and ways that select inhabitants very cleverly manage to help this colony survive against various threats.