I agree (although in the slide it did have more purpose than just carrying ammo).The last slide looks a lot like the T-14 Armata. And I have seen similar proposals from the Russians of adding the trailer vehicle in combination with putting a 152mm gun on the Armata platform. I assume that is what is seen here.
With 152mm shells you have a lot less space in the vehicle if you want to store the same number of shells, hence the trailer. It is still a bad idea, the requirement for a trailer vehicle was one of the reasons for the US cancellation of the Crusader howitzer in the late Cold War period, it increases the cost of the platform quite a lot.
You are basically making two tracked armored vehicles with the capabilities of one. Today ammo reloads are typically carried by much cheaper trucks.
The chinese proposal on the other hand (post #228) is a bit more interesting since it seems like it have more function and purpose, and it seems like the back vehicle could be detached and operated remotely or the likes.
Not to mention with UAVs and the likes, it can help give awareness to the tank and probably also the whole tank squad/platoon w/e.