I've been around so long that I start to think I've seen the worst possible negligence and chicanery imaginable in this industry. This reminds me that things can always sink further.
Forza Horizon 3 just got its first expansion, Blizzard Mountain, yesterday. Along with the not-free expansion comes a mandatory game update, which prepares the game for the expansion. After the update, the game takes the player through some cutscenes, and eventually to a screen where they can press A to buy the expansion, and B to back out. Except that B does not back out. B does nothing. At this point, the player is stuck with no recourse but to exit the game.
Here is a thread on the issue. It also links a reddit thread where some else is experiencing this. I have not found a single post claiming that playing the game is still easily possible without buying the expansion. I have been looking.
Luckily for me, I always wait a day or two before allowing changes to my game. So I have dodged this update, and can still play offline. I will not be blackmailed into buying this expansion.
As is typical for them, Playground Games and Turn 10 are completely ignoring their player base. They haven't said a word about this. I think they need questions from quarters less easily held in contempt. So I'm putting this out there. Hope springs eternal.
Edit: They're now working on a permanent fix, and issued a workaround.