Likelihood of this being the one to gain approval?
Sadly, this ETF hype feels quite like the hype around merchant adoption during the 2014 bear market. Back then, it was "Dell adopted BTC!" or "Paypal is thinking about adopting BTC!"
A CBOE ETF won't save you from a bear market anymore than CBOE futures did.
I really think approval is doubtful in any case. This one, that one, or the other one.