There a wide spectrum between "some removed from circulation" vs "the entire thing ceasing to exist". think of this as a 400k token burn.
But ETH is a mathematical construct. It should be true in the limit up until the very last measurable quantum of ETH is erased, and the very last bit holds the entire value of the cryptocurrency.
To put it another way when does “deleting eth is good for eth” cease to be a valid argument?