He's talking about the 4-pin headphone output on the front. I think it depends on the type of the connector, to click satisfyingly it needs the notch on the top and not all do.

I have some connectors that sort of click satisfyingly but I also have at least one adapter (on the right) that is extremely unsatisfying, it just sort of goes in and there's no clear point at which it's fully in. The black one is OK and it is clear when it's finished pushing in but it doesn't "click". Only the middle one clicks.

I don't think I've ever seen 4-pin XLR headphone outputs with a physical release button. That's for the interconnects at the back.