Seems like a big waste of money. Why not just make do with hybrid buses? There isn’t a need to take on venture level risk as a city government.
The risk is always lower on the other side of the fence.
I mean, this seems to be one particular manufacturer having trouble rather than anything else? A plurality of new (urban) buses in the EU are now battery-electric as of last year (36%; the rest is mostly a ~even split of diesel and diesel-battery hybrid), and AFAIK practically all new buses in China are. Their mistake here wasn't electric buses, it was going with a small, new company. Most electric buses are made by companies with significant experience making diesel and diesel-electric buses.