Yeah but we’re not supposed to think about that. Just as we’re not supposed to think about all of those Ewoks that should have perished as billions upon billions of tons of burning wreckage from the Death Star came plummeting toward Endor :-P
Ewok apocalypse wouldn’t’ve happened. It presumes that the Death Star is relatively solid, but it probably was more hollow than a great, big soap bubble. (Seriously: an armada of spacecraft fly through open space past structures which themselves are probably more hollow than any modern skyscraper, and probably more hollow than any hangar.) Also, given that the Death Star would have to be at an geostationary (endorstationary?) orbit to be protected at all times by the shield generator, it would have been so far away that the vast, vast majority of its mass would have been blasted AWAY from endor or PAST endor, and probably would have eventually burned up in the atmosphere of the gas giant around which endor orbited.
Wait, you ask: would an endorstationary orbit be that far? Orbitting a massive gas giant, Endor would likely have been tidally locked to its host planet. Our moon is tidally locked; Mercury is tidally locked to the Sun. That means that its day is about as long (rotating period) as its month (revolving period). That would explain how so much got done on Endor in one night: that night could have lasted days or even weeks.
In fact, the BEST guess is that Death Star didn’t even revolve around Endor at all; it would have been SO far from Endor, the gravity of the gas giant may have made a stable endorstationary orbit impossible. Instead, it may have been following Endor at a fixed distance in the same orbit as Endor. This is possible at 60 or 180 degrees away. At THIS distance, the Death Star may have blown up while having very minimal effect on Endor at all.