BU is supposed to activate with 75% of the hashrate, I thought. It’d take a concerted effort across multiple pools to make BTC the longest chain, and the shift could be seen months away, in all likelihood.
Also, you’re entire article is predicated on BU working from a technical standpoint. Why wouldn’t Core just merge the code in, when it becomes apparent that BU isn’t the disaster we were all promised? We could avoid the entire dilemma by doing that.