FWIW, I think they probably accepted more than 10% of the interviews before this week. I was at the Second Look Day last week (4/22) and there were three people from my interview day, and I know of at least one other accepted student from that day. That's 4/20, which is 20%. And another person there said there were four people from their interview day at the Second Look Day as well. So I suspect they may have been letting in more than 10%.
I thought the way it works is that the 10% represents those who are outright accepted, while the rest go on hold or get rejected. Thus isn't it possible that those other accepted folks were only accepted after being put on hold?
Regardless, I don't think any of this would affect waitlist movement, because aren't there enough acceptances handed out to fill an entire class at this point? If that's the case, then the initial number of outright acceptances wouldn't affect anything.