They don't mention it in the article but do these big buses use regenerative braking? Seems like a no-brainer to add on considering all the starts and stops a bus does, but maybe it's not worth the extra cost for fixed route operation?
I believe they do use regenerative braking, yes. I say that because I ride BYD busses on a regular basis, and (especially on older models, which are not as smooth) you can feel (what I think is) the jerk of regenerative braking kicking on.
I believe most electric buses do: adding regenerative braking to electric vehicles requires little additional hardware (the electric motors can act as generators, etc.), so it is certainly cost-effective.
They do indeed. Same as trams, trains, or trolleys