It's not actually that concerning. RN's pods are vended via npm not trunk so trunk going read-only will not have an outsized impact on RN.

The risk is that over time Cocoapods will no longer work to integrate dependencies with ways Xcode wants them to be.

Switching to SPM is a massive undertaking for a large project with many intertwined dependencies and configuration options. It's far less configurable than Cocoapods with basically no scripting options during install.

Their progress already is pretty decent!