I played Nick Riddle with Falco in tourney a month or two ago for two sets (I actually use Falco, though it's not in great shape or anything).
I went 1-1 in winners (went MK 3rd game and won) and 1-2 in losers. He's really ****ing good at the matchup, though I still think Falco ***** ZSS. 7-3 is an exaggeration, I'd say 65-35 to 60-40 is a lot more reasonable. Falco has the options to completely shut down ZSS but Nick does a lot of stuff every other ZSS player doesn't understand and can't emulate and I think he's figured out ways to make the matchup a lot closer than previously believed.
Yeah there's no doubt ZSS loses.
I think a long time ago, I said something which I think accurately sums it up:
ZSS' options are limited, so you're going to get hit a lot. However, the options you do have are effective set-ups and generally deal more damage than Falco's superior option (laser camping, which ZSS can't really fight very well). Once she gets inside there are plenty of damage opportunities, and they will generally deal enough to keep up with Falco in terms of damage done. It's all about getting inside, though, which is touch-and-go. If anything, this match-up is more frustrating than it is unwinnable. There are also a few wildcards at ZSS' disposal, such as the 0-40% chaingrab she has on him, the dsmash lock to 40%, and the dash attack lock to jab which forces Falco to use his up+b. Any dash attack on Falco at mid-percents is a gimp opportunity.
ZSS at the end of the day though has only a few mediocre answers to Falco's laser camping+side-b shenanigans. Very frustrating. :\
I do think 4/6 is the most accurate, however this match is very close to unwinnable on Final Destination. I'm still not sure why NR didn't ban it.