Those aren't "your" relays. Your relay list is still the same. They didn't force anything... No one can force anyone to change anything on nostr. You would need your private key to make that change. This change is to facilitate full outbox. Which is how nostr is SUPPOSED to work. The only reason there's a bunch of relays you see is those are relays in the list of relays of the people you follow. Now when looking for a note, your client can look for your follows content in their relays.