I mean, what else is left? and I still want to know if heavies will at least be able to climb stuff or not.

They will. Just they are not as agile as mediums of lights.

What's left is Resistance customization. I say that because the new "Ready & Able" trailer only featured Security customization. Umm they could show new maps. They could show some more gameplay rather than trailers. They could show some features like the Fireteam or the challenges. They could show a couple more attachments if they haven't showed them all already.

Also as far as we know heavies can climb things that are waist to chest high

They could make an actual trailer about sound, something a little more in depth than "A Choir of Guns".

Only waist high stuff.