I sure hope Disneyland Resort brings back the spooktacular Haunted Mansion tour! It looked so incredible! Typically, that tour is near Mickey's Halloween Party, so if it does return, I would think ticket sales for that event would be available late July or early August. I would keep an eye on the Disney Parks Blog for specific information and dates as they are the first to talk about such events.
Please let me know if you have any more questions as you plan your visit!