[lxgr]

> The new Iridium pagers are two-way as far as I've heard.

Apparently that's optional:

> Iridium Burst-enabled devices can be configured as receive-only so that no transmissions are made, a feature valued highly by some customer segments.

(from https://www.iridium.com/services/iridium-burst/)

> I think the service is finally being decommissioned due to the Iridium Next satellites not supporting it anymore.

If that's the case, it would have been inoperable since 2017 – they deorbited the old satellites immediately after confirming deployment of the new ones.