It was inevitable after they were bought. Funny how they lied about this up to the last moment still. It's also blatantly illegal. Well the game is readily available at the common piracy sites though.
Edit: Also from the text of the announcement blog post on cross account progression: "Rocket League’s cross-platform progression is made possible with an Epic Games Account. So, creating one or signing into your existing Epic Games Account is the first step of the process. You'll be prompted to do this when you start up Rocket League for the first time after the update. Once that's completed, there are a couple of different ways to connect your Rocket League platforms to your Epic Games Account and complete the process for cross-platform progression. "
The EULA not being visible definitely sounds illegal, though. Really absurd oversight.
This is the key part, it should be BEFORE you install the update, and with "Do you accept these new terms and wish to install"
Not like it is today
"We have forced these new terms on you, and if you do not accept you lose all access to this game"
as there is no easy way to rollback to the previous version that worked
Rockstar games for instance required a third-party account to play GTA5.
Thank God for brexit, couldn't be having any of that free trade and consumer protections