Developers of every single fork will have to take care of that issue on their own. Litecoin, which is a fork of Bitcoin, has already got its client patched. I wouldn't expect any reaction from the developers of, for example, Bitcoin Diamond, Emerald and any other Bitcoin clone which nobody uses.

@achow101 Do you happen to know why the minimum transaction fee is going to be lowered in the 0.18 release and not in the 0.17 one?