This would maybe help clarify that the reference to the event can be called "address", something which seems part of the Nostr jargon but not really consistently specified (although consistent with the tag name for such a reference being "a").

However, I'm not convinced it's a good name. "Addressable event" merely suggests that you can refer to it, which is true for all events. "Replaceable" gives more information about what they actually are.