Austman’s comments are correct but even if it doesn’t have a sign, that doesn’t mean it’s not a designated exit in case of an emergency. It may just mean that there’s no sign.
Your scheme should have council approved maps showing routes and assembly points and if this gate is on an emergency exit route then it should be openable from the inside.
Apart from that, any strata committee decisions can be overturned by a majority of owners at a general meeting.
If you can get 25 per cent of other owners (by Unit Entitlements) to sign a motion, you can call a general meeting to overturn the decision.
If you can’t get the numbers, then it’s unlikely that you would prevail even if the item was raised at an AGM.
Meanwhile, you could send the committee a “please explain” as there may be other issues that they are trying to deal with that they have decided not to mention in public.