Its not the worst example but the fact they waited to add them in after people already reviewed and boughtbthe game is shitty.
The worst micro-transactions for me is Street Fighter V. At launch they had 5/6 or so extra characters ready, but put them behind a paywall for £5 each which adds up. You could unlock them through gameplay but if you played online and won every single game for 2 hours a day it would take months to unlock every character. And we know that if that wasn't there it would just take completing the story mode with different characters to unlock everyone.
I couldn't continue playing after seeing how impossibly long it would take to 'earn' characters.
If anything, I find that Activation screwed themselves for adding loot boxes in later. Everybody that I know that plays BO4 couldn't care less about it now because we've all been playing the game without it already. And being an avid BO4 player you actually unlock tier items fast and get free loot boxes pretty fast too. If they added loot boxes in the beginning it may have been a different story, but also Activision wouldve been shamed upon moreso.
Man you're right about SFV, that was just too much for me. I liked that they gave the option to unlock the characters for free, but they make you grind forever. Probably the worst example of a game that gives you the option of free characters that also has the option to buy them. I have the game (friend gave to me), but I think i rather wait for Ultra SFV when its all done lol