Would this preclude you from seeing the thread?
(Obligatory “who said that?” joke.)
No, the thread would still appear in the forum listings like any other thread, just the OP itself would be hidden (with the usual message that the poster who made it is on your ignore list and to click there to see the message.)
You can’t mouseover and preview threads if the OP is on your ignore list.
Try it yourself. Find a thread somewhere - anywhere. Put that poster on ignore, and see what happens. Then go and unignore them.
The thread is visable, but OP is hidden.