It's -1 for sure. We will be destroyed by lasers if we don't approach and our approach game isn't great. Other than that, no huge threats offstage, really, we want him in the air as zss always does, and we can gimp him well if he makes a poor offstage decision. Lasers are the biggest hurdle, but they can be managed if we explore all of our options. The most useful of which are crawls, SHADs maybe, or CPing a cramped stage where he can't laser camp well. Prioritize approaching Falco while anticipating his annoying frame trap attempts from lasers and predicting his phantasm patterns (which he should usually be doing the moment we start closing in on him). And, of course, be looking for an opportunity for a ledgegrab gimp at all times if he ends up forced to upB offstage. The main thing about this MU is to catch on to Falco's patterns early because they should be noticible if camping is his primary option lol. Figuring them out will allow us to approach consistently and have more opportunities to exploit our strengths.
In terms of matchup-specifics, look for an opening for a 0-60~% Dsmash chain. He'll be attempting Dthrow chain grabs when we're at low percents, so watch out for that, too. If we Dsmash Falco offstage, a footstool-to-timely ledgegrab will gimp him. Jab will stop phantasm, which is useful at the ledge. Ban FD.
Honestly, this matchup has not changed at all for us, as most of this should be known. Apparently, the only difference as of late is that zss has proven her potential in this matchup enough to not make Falco a counter character. As such, once we are able to approach Falco consistently, this matchup is very manageable.