Who said this? A businessman will always be wise as a businessman. Why would they gamble their thousands of bitcoin for this new creation? It's just odd that they will let their profit go into the thin air, no way they won't do it. Probably they will but maybe 10% of their total bitcoins.
Actually it was Roger Ver himself who said that first:
https://cointelegraph.com/news/roger-ver-i-will-sell-my-coins-to-buy-more-useful-bitcoin-unlimitedAlthough he was referring to BTU, I believe he is doing the same for BCH - specially when the pushing for BTU has not worked out (yet?).
I read from an article or blog somewhere this week that he can others will sell Bitcoin to buy the BCH. The article did not mention how much they will sell though. You were right that a rational businessman will not take that kind of chance and would understand the meaning of diversification.
If he said that he was just about to go with BTU then it was only for it. But who knows on what he's about to do. He's been doing things and push something that he thinks will support him by the community. Why he doesn't want to stick with bitcoin so that everyone of us will live happily ever after and it will never end.