Supposedly all 4 House sets will be released this year, one per quarter, also they will have 2 availability windows.
When House 1 returned I think it only lasted a day or two online. So if they made the same total number of units for both sets, say 30K, perhaps they did 20K followed by 10K for House 1 and reversed it for House 2 10K with 20K still to be released in June. But that is just speculation.
ETA: The All Knowing Bird should chime in soon with some clarification.