It's fucking nothing. Some mexican dude has a good union job with the local government that gave him enough money to buy a daycare business to give his retired gramma something to do, and code enforcement shut it down for the stupid reason that gramma was the only adult in the building but the building has TWO rooms! You need a supervisor in each room! That changed the business model from gramma working for free to the family having to hire people they can't afford, so they shut it down and you have an abandoned daycare that nobody goes in or out of.

Everything else that came up had a reasonable explanation. The first responses that kicked off the speculation were LARPing or heavily overreacting. The chinese import records were from a corrupted database that had fake records for other companies. The family started keeping watch on the site after it became a tourist attraction and dickheads were carving pentagrams into the building, so you had "mysterious" mexicans going in and out. No one knows what the rabbit means but it could have been added by a local tagger.