Ideally though, if this became law, you would be accounting for the fact you might have to swap out the server implementation into your initial development of the game.

Also, some of those tools you might not need for production client code. Yes it’s gonna be a pain in the arse to develop server code without those tools, but not necessarily impossible. You could release server code with those tools stripped out, or able to be configured to work with those tools if someone else has the license for them.

In essence, you could modify the client to include configuration points that can point to specific servers, and then release documentation to say “Hey, this is what tool was originally used, these are the kinds of packets the client is sending (and whether they are expecting a response), and these are the kinds of packets the server is sending to the clients”. You then leave the actual server development to whoever wants to build one. That is, effectively, how private MMO servers are made, but regardless of the type of game, you’re still sending UDP packets to a server and receiving UDP packets from the server. You just need to know the purpose of those packets.