We had some issues where STBs would not easily boot back up when the power came back on. The MoCA setup seems to be finicky in some cases. Or it is also sometimes due to the MoCA not being hooked up correctly in the first place, which we have seen a few times.
In some cases, all STBs need to be unplugged from power, reboot MoCA (make sure it is using COAX OUT), plug STBs in one at a time. They may do software upgrade.
Today we did not have to replace any MoCA adapters, it was just a matter of power cycling in the right order and making sure it is plugged into the COAX rather than the RF on the MoCA.
There was one case where we had to replace the power adapter to the MoCA adapter. It is not out of the ordinary to have this situation come up a handful of times after a massive power outage.