That would be the most logical conclusion.
A cougar. Many said no big cats had been seen in that area.
When such an animal wants to hide, they will lie in wait, and not be seen till it’s too late.
The sounds aren’t the same. And if one is familiar with wolves, there’s a difference there, too. Some sound close to a vixen in heat but that gets all twisted around when the call ends with a whoop, whoop!