last year universal wanted Last of Us and early negotiations fell through because Last of Us got delayed. They then negotiated Evil Dead, built the house and then the IP pulled out because they delayed the release.
Scarecrow last year was going to be a full house until they managed to get another IP signed on. It then became a scarezone.
Scream was going to be at HHN 25, Universal started building the house and then they had a disagreement over props used. Scream pulled out at last second.
Last year, HHN also had a disagreement over The Weeknd licensing. To compromise, we ended up with very few pieces of Weeknd merchandise.
IPs can pull out for any number of reasons. Would they pull out over a board gossiping, no probably not. Would they pull out over a full leak of the planned house, leaked concept maps or leaked pictures? Absolutely.