There might be a difference, but there isn't for the consumer in this case, if that is what he really cares about.
They are allowed to publish everything on the 25th, that is still in the pre-order window, and everybody can cancel their pre-orders or wait until then to pre-order in the first place.
Also, not being mentioned here is, that another advantage of that staggered approach is that smaller reviewers get the phones right now and have a chance to publish their reviews at the same time as the big boys. And the big boys also had the option to opt-out of the early units, if they disagree with Google's way of handling it - and get it now, like the smaller guys.
I also think MKBHD did do similar stuff with Apple in the past, was it the new Mac Pro by chance, where he was one of the chosen ones who got one really early but couldn't show everything? I vaguely remember something like that.