Well, I now have Verizon Messages and Hangouts working as they did before, with notifications.

I have written out the steps below. I don't 100% know if they are in order or they even need to be in an order. But, it took a lot of playing around, and I got them both to show me text notifications as they did before.

Link: https://www.techadvisor.co.uk/how-to/google-android/sideload-apps-android-wear-3673967/

Watch IP Address: 192.XXX.X.XXX:5555 (Find Your Watch's Specific Number)

Download Verizon Messages Mirror Version 6.6.7
Download Hangouts Mirror Version: 26.0.20
Uninstall Apps From Phone
Uninstall Apps From Watch
Restart Watch
Install App (One at A Time) On Watch Via Sideloading
Disconnect Watch From ADB
Install Old (Mirrors) Versions On Phone
Go Into Play Store On Watch & Install Apps From Phone (One at A Time)

Turn Off Auto-Update On Each App On Your Phone
Turn Off Auto-Update In Your Watch's Play Store