Insider builds are no longer rolling out, and this might be for the greater good. Microsoft has announced that they will pause Fast and Slow ring builds starting 12/2 Friday, so as to prepare for UUP service.
UUP or Unified Update Platform is a new way of delivering updates where you only recieve the changes, rather than a full builds. This would make updates smaller by about 35%, as claimed by Microsoft.
To prepare for this, Insiders PC builds have been paused for a while. Though duration of this pause is unknown, once resumed insiders will start recieving updates using UUP. For all the insiders currently on older builds, seems they’ll have to wait for a while.