They are explicitly pursuing a demisable sat design. Note - despite other posters claims, this is not a requirement and there are other approaches as well for

They are explicitly pursuing a demisable sat design. Note - despite other posters claims, this is not a requirement and there are other approaches as well for the safety side here. The most common is to deorbit into the ocean (the sats are maneuverable) with a failure rate and part hazard rate low enough that remaining risk is minimized. I would expect they would deorbit into ocean / near non-populated areas for other reasons as well.