Looks like they got a pretty good response!
https://twitter.com/Gollancz/status/690525519041925120
They said they think they got about 600 submissions.
That's a fun picture thanks.
Note that they are talking about booking a meeting room. Makes me wonder if one of the reasons they want paper submissions is so they don't have to print them off themselves. If you are taking yourself off to a meeting room (away from phones and email) then paper makes sense. (Also, if it were me, I'd prefer to read on paper, not the screen.)
So we roughly know the numbers submitted to Hodderscape and VG. Angry Robot submission is still open. When that closes, there is going to be the chance for some interesting statistics relating to how many were submitted.
HS - email submission and as many manuscripts as you like
VG - paper submission and as many manuscripts as you like
AR - email and only one manuscript
So far, VG goes have fewer submissions than HS, so maybe sending paper only has reduced the numbers. BUT maybe people who submitted multiple manuscripts for HS have not submitted as many to VG.
No way of knowing...... but lots of room for speculation.