You're still free to use whatever version you're currently using under the terms of the original license.
From an ethical point of view, it's worth thinking about whether you'd like to respect the wishes of the author(s) of the software, even if you are not legally required to.
From an ethical point of view, it's worth thinking about whether you'd like to respect the wishes of the author(s) of the software, even if you are not legally required to.
IANAL.