Well damn, I'd be surprised too but the man is 60 and Jake is what? 27 or 28? That's a crazy age difference. Jake is basically like fighting an old father. I hate to see Mike fighting at this age, even if it's just an exhibition which is not really a serious match compared to professional bouts. Mike may had crazy boxing skill sets, but nothing beats age though all of it will deteriorate. 
Anyway, this is more about money though than being a sport. Purely an entertainment only. As per boxing fans, who wouldn't want to see Mike inside the ring again. Sports fans nowadays would love to see legends strapped in again after a long year of retirement and they are willing to pay a crazy amount to see it happen and so this kind of events happens. If anyone benefits this the most, that would surely be Jake Paul.
And to answer the question, NO I wouldn't bet in any exhibition matches. Simply because 1. It is not a serious fight and 2. They have their own set of rules which could be a little complicated sometimes.