As many have pointed out, Wilbur plus a debuffer (e.g., Sabina, Sonya, etc.) removes the Spirit Link from your opponents. It is also important to keep in mind that a limited area debuffer can and will do the same (e.g., Domitia, Frida, Evelyn).
I have had raid situations where I have fired Wilbur and then deliberately removed the link from 2-3 heroes, either with the intent of attacking them, or killing the other 2-3 still linked via their shared damage (same amount of damage shared between fewer heroes leading to a faster kill).
The bottom line is that you should have a plan for how you’re going to use Wilbur and use the spirit link (removing it and exploiting it are both ways of using it) before you go into the raid / map. That way you’ll have thought about the most likely scenarios and brought along the correct complementary heroes.