The rest of the coins will just have to be worth more. Bitcoin is divisible to 8 digits. When 1 sat is 1 $ (2018) it will still be a good problem to have.
Idk, burning $10 of coins increases the value of every other coin by a tiny tiny tiny fraction. A donation however, increases adoption in countries that could use a stable currencey.
I have mixed feelings about it, especially with Bitmain. If the stated purpose for doing it is to make everyones coins more valuable I think it's dumb. How about pay a marketing team?