We have already talked about this. In the end it comes down the index for the instances that bsky maintain it will inevitably be the dominate ones vs others who run AT Pro.
It would be all good if the index is shared via DHT, bittorrent, ips or other means. Same goes for the google search index, etc.
In short, they're actively working on making AT as neutral as possible.
[0]: https://docs.bsky.app/blog/taking-at-to-ietf
[1]: https://datatracker.ietf.org/doc/bofreq-newbold-authenticate...