Would it be worth it to add a List called “Online Players” or something of the sort to make it easier for Multi-Player Games? It could be like the timer or username variable in that they are there even when you don't need them.

This idea also has many other benefits, this list could tell you what players are viewing your game at any time, helping people see if there friends are on, and overall encouraging more than single player games.
Also the servers or whatever is chosen to store the list would not have to store the list unless it was in the code, saving much data.

This idea has,
A Low Floor, Is an easy concept in that it is easy to use and understand, could use simple blocks to operate it like “If contains player”, “If player leaves”, and/or “If player Joins”.
Very Wide Walls, This list has many possibilities such as seeing how many people are online, checking if a friend is online, and/or telling others that a new player has joined.
and finally High Ceiling, This list has many possibilities more than anyone could list and encouraging people to get into a new set of games and game making. This list would not only help me but many others.

Looking for Feedback from everyone!

Scratch is a bare-bones programming language. Multiplayer features will most likely never be added.