Satellite 6 - Incremental Content ISOs

I am currently going through the process of configuring a disconnected Satellite 6 server and was surprised to find that there are no Incremental Content ISOs available for RHEL 6 / RHEL 7 in the Satellite 6 downloads page.

Users are provided with the message:

Incremental Content ISOs are not available for this product. 

The base content ISOs end at 2015-09-29, which is now over two months old. Is there a reason for the lack of incremental Content ISOs for Satellite 6? what solution should disconnected sites be using? The documentation I have read still references incremental Content ISOs.