>>543751967
>Has any gacha ever made big changes to the monetization without taking the game down and relaunching?

Actually yeah.
FGO 9 year ago did it.
For their first anniversary they
>reduced the cost of the singles
>reduced the cost of the multi
>increased the numbers of gems you could get after buying packs with real money
And they didn't refunded any currency to the players that spend rolls before this change.
The players didn't bitch about it either.