Technically, yes. The
Google keyboard was said to be used to monitor what user are typing or copy which is why external open-source keyboard are advised for Android phone users.
I mean on a pure Android without any installed apps excepting crypto wallets + google play
However, for total privacy you'll need to have some privacy setup on the phone since you're going to have Gmail account on the phone.
Am more afraid of external keyboard which you dont know the source/developers behind it. Most of them can be very suspicious.
I understand your stance.
You don't want to be in a situation where you're running from the worst thing and end up with the worst one.
But if you look into the link I once added in my post, which is the link to a thread I once created about this type of issue. You'll see Exodus privacy, which is a non-profit privacy platform that verifies every open code app, which you can check the keyboard source code before use.