Big Willie It seems like the Gabriel situation was agent/Saudi transfer related, and is now over. I'm guessing his agent tried to leverage Saudi transfer interest into an improved contract, but who knows. Even if they do plan to phase him out, you can't convince me they played Partey at RB for sporting reasons to begin last season. Arteta seems to love him and trust him.
I also don't see Calafiori as part of some elaborate plan, or even see us targeting specific profiles. We seem to be looking to reinforce the whole squad, targeting players Arteta/Edu like who are available at good prices, with lots of possibilities with positions and roles.
We had four starting-quality defenders last season: Saliba, Gabriel, White, and the injured Timber. Arteta seems interested in signing a fifth. Gabriel could lose his spot just like any of the others can: if Calafiori pans out at LCB/LB, any four of that five would make a viable defense.