It needs to be clarified that in term of number of coins, BU does hold more BCH than BTC AFAIK. Your figure is the dollar value.
I am disappointed in BU to be honest. Little skin in the BCH game does not instill confidence.
What's more important is the BCH price. If the price goes up, they will be forced to mine BCH. 5 Billion market cap is just so Puny. Not even close to adoption numbers.