RAK2245 substituted by RAK5146?

Until now, I’ve been using the rak2245 with Raspberry pi 3 B+ and Chirpstack.
I’ve heard that rak 2245 has been substituted by RAK5146, is this true?
If so, which model should I choose (I don’t use GPS), with or without LBT option?
Is it compatible with ChirpStack Gateway OS?
I assume I need to add the RAK2287/RAK5146 Pi HAT converter board?
Thanks for your advice and clarifications