I honestly I don't think Asus is going to have an update for it. It's been a while since I heard anything from it. Also, everyone's been saying the newer versions, and the ROG series getting priority over the Zen 6. I'm in the same boat as you. Kinda...
I just went through with that today, and in my case, I had to go to a att store, and they had to activate it manually. But if you have att, you will probably have to get a new phone because asus probably won't have an update for zenfone 6 to use volt...
I'm gonna take it that there probably won't be any updates for the Zenfone 6 anymore. Other than patches and security fixes. My zenfone 6 is probably gonna be a $500 paper weight after 3g towers get shut down cause I'm with att.