No, the security checks are quite obvious. If anyone sets off an alarm going through the scanner, they're pulled aside for a more manual check, just like entering the theme parks.
If they really have no security checks for people arriving by bus, it makes no sense. There are checks for people arriving by boat, walking, rideshare, and driving/parking in the garages. Not screening those arriving by bus - maybe that's 25% of the people arriving? That makes no sense and defeats the purpose of screening in the first place!