Just a random thought. If you really don't/can't release Gang Houses now after almost 4 years of the game being released, could you perhaps consider adding more Housing Themes?
I can remember Era has a specific shop for Housing themes, so perhaps something similar could be implemented. As well as perhaps selling specific housing themes on specific holidays/occasions. For example; Using the Pyramid instead of a House in the outside level of a house and the inside could represent somewhat of a spooky styled house.
Having more, "cooler" housing styles would really be great whether or not Gang Houses will be added to the game. Each House is only 2 levels large, so it wouldn't be an extremely difficult task to do. As well as the fact it could be something else to look forward to during holiday events.