I contacted the PI who interviewed me and he said that no news (rejection/acceptance) meant waitlist at this point. They didn't even bother to send out emails, which pisses me off to be honest. I hope it helps!
Do you guys have any news about the waitlist? As far as I know there's no ranking, but I'm not sure if the waitlist goes by groups or the whole Media Lab.
I also saw that the rejection email said that they were accepting less than 3% from a total of 900+ applications, which is half of what they accepted in previous years (5% of 1100+).
Are you getting requests for more interviews? Did your PI get in contact with you?
I also got waitlisted, but I think that for at least some groups it means that they still haven't made the final decisions. I also got contacted by the PI directly to continue the conversation and set up another interview.
For those in the waiting list, I'll continue suffering around here in case you need me
Calling might be a good idea if anyone is in the US. I assume that they didn't reply to anyone who contacted via email. At this point feels like this might go on next week.
There are a few fellowships awarded before the application process, but it might depend on your country. An example is Fulbright, which is available in many countries all over the world.