Can the Platform SDK 72.0 let the player know when another player is joining their game?

To be clear, I don't mean by requesting a separate server system like photon to find this out.

I need a message send from whoever is joining you, so the player receiving this can start a server at the same time. So they can connect to the same photon server using same lobbyID/MatchSessionID server name.

I don't want to have each single player starting a game to run the photon server at the start just incase it might become a multiplayer game later when a player joins.

I also don't want to have be activate multiplayer within the game manually by the player.

I just need a way of knowing if another player has clicked to join me with same lobbyID and matchSessionID, nothing more than that. This is what I thought the joinIntent message would do.

If this isn't possible currently, then can it be added into the next Platform SDK?

Thanks in advance for any help!