More info to the above here:
I thought that the questionnaire they received might have just been from my security POC to kind of square things away before submitting it to OPM, but it was sent from OPM as an "investigative request". So i'm assuming it might have asked to arrange a meeting of some type at some point as well, but i'm not sure entirely.
Edit: One of my best friends who I listed as a reference also got one. This is either moving fast or they think i'm some sort of potential scum lol.
Did your friend get something through email or snail mail?