[inigyou]

If they converted to IPv6, they could easily have a globally unique address space. Real globally unique, not probabilistic.

[oasisbob]

The fact that the network concentrator co uses DoD v4 address space to avoid conflicts implies that their clients are bringing v4 addresses, so IPv6 is utterly irrelevant in this situation.

[inigyou]

It's common for a network to address its own devices with v6 while carrying v4 traffic either natively or by tunneling. Saves v4 space.