While this (the second paragraph in particular) is a valid point, I'm not sure I see how it applies here. The value of a stock on an exchange is an aggregate of that stock's value to many investors. The value of a stock to any one buyer will obviously be different, whether it's a grandma picking her own stocks or a large institutional player considering a buyout. The former is relevant to the IPO in the short term, the latter not so much.

Basically, I'd expect that the aggregate value on an exchange (as opposed to a buyout) going forward is going to tend to be more about the fundamentals (as the only thing that all investors have in common information-wise). At least in a scenario where there is no obvious buyout possibility in the short term.