Somewhat. They can certainly maintain a list of known IP addresses. Those IPs can be changed.

When they change, you as a user need to be able to find the new addresses. Whatever mechanism you can use, your ISP can likely disrupt too. For instance, they can DNS block the API that returns the list of possible endpoints (as sometimes happens to Proton where I live).

You can then counter by using private DNS. It’s a cat and mouse game.