Seriously... he shows the pieces he had to remove in order to get this working and he compromised the water-proofing of the phone. How is that, in any way, an equivalence to "void" or "empty space"?
The "new phone" no longer has a working altimeter, is not waterproof, and has major structural issues now. Anyone saying that there was just extra space there is being ignorant of the facts shown or is being intentionally disingenuous for some reason.
I think we're going to look back to the dawn of smartphones as being particularly anti-consumer, anti-privacy, and typified by corporate dishonesty.
edit: I see the narrative is "but, but the iphone 8 will be too thin for it, trust me." Then there's no reason to do it now other than crass monetization at the cost of the consumer already invested in wired headphones and being forced to do a pricey upgrade. Not to mention, simply migrating to a thinner analog audio plug like the standard 2.5mm connector which is merely 2mm thick and can use a minijack to 2.5mm adapter can be gotten anywhere and cheaply. That would be a trivial change and allow Apple to make a very thing phone. Instead excepting a DAC on every headphone or having a DAC adapter is clearly a monetization scheme.
Apple has been a dishonest, anti-consumer, cargo cult designer since the beginning of personal computing and I can't wait until their time is over.
Just one example: The single button mouse. For the longest time the party line was "it's better for reasons", but everybody knew it wasn't which is why the first thing anybody purchased after buying a new Mac was a multi-button mouse. You didn't even have that choice with their laptops unfortunately. Internally, Apple's reasoning for keeping it was that it differentiated them from PCs and they didn't want to appear to be stealing from PC designs.
Funny... I thought they removed it to save space. Apparently they needed space for that void?