thats a kind of tail emission, the one implemented in Monero, for example, is progressively decreasing unless the new emission is something like 3 xmr every block, and from then it will be 3 xmr every block forever (unless shitcoin dies).
I think constant-value-emission like that is still another way to tend with different paces to ~0% inflation, so still pretty the same functions.
Is more a question of "numbers choosed to put in the functions" that "determines the speed" and makes the differences.