I think Paul summed up most of the counterpoints nicely, but I'll add a couple more.

The Dynamic Island is primarily a status/notification area and I don't think one is going to be interacting with it all that much. And, if you do do, you'll be probably be targeting one of the active areas on either end. Not on the camera itself.

Besides, what do you think would happen if/when Apple ever did an under-glass camera? You think that section of the screen is going to somehow magically stay fingerprint free?

Your third point, however, has something to it. I don't think Apple would have gone to all of that trouble if the silly thing wasn't going to stick around for awhile.

And that tells me that Apple isn't planning on compromising the camera and sensors with under-glass versions that, as we've seen on other devices, simply don't work all that well.

I'm all for Apple innovating "more aggressively". But I'm also perhaps somewhat more pragmatic about what physics and our current level of materials science will allow.