The gate……
"Clear the gate" "The gate is good"
Are a terms used in film making meaning the area (the film gate that opens allowing the film to be threaded through the camera behind the lens set) in the movie film camera is free of dust and debris. No dust threads etc. in the shot .
Clear the gate /Check the gate: is done after and or before each shot of a scene.
Gate is good/ gate is clear : means its clear ready to shoot.
I've heard all the aforementioned terms used on a set.
These terms are seldom if at all used now in that almost all new films are digitally shot/filmed.
I think Martin Scorsese was the last director who insisted on using film but due to pressure he to converted to the digital format.
Hanks was making a reference to the nostalgic aspects and how the industry has changed.