I don't really get the point of this when we still know extremely little about the B-21. We don't even know how many weapons bays it has, let along what its bays can carry (beyond presumably the LRSO in some fashion). Hell, we still haven't even nailed down wingspan with estimates ranging from less than 130ft up to 150ft.
I think my kid can even tell its big enough for two weapons bays. Wingspan is totally utterly irrelevant. The volume of the aircraft is what matters. No we don't know that but its not as small an aircraft as was imagined. The gear are a good barometer. They're not going to put 1 bay in the centerline and leave all that real estate alone. The aircraft would be much smaller and not so much girth underneath. Knowledge people there said it was not significantly smaller than a b2. Clearly 2 bays and clearly also room enough for defensive\offensive aams.
Also the windows have nothing to do with laser protection. My office has windows that turn opaque with the push of a button.... That's been around a long time. The windows are the minimum necessary for the human biology dynamic of needing to look outside when flying... From time to time. Flying isn't like being in a submarine.