> What are you basing this prediction on?

The fact that most foundation movement is caused by ground compaction, sliding or buckling, and outside of some very special circumstances, like building on a wet clay riverbed, the ground does not simply suck things down into it. The most likely reason it moved is that the original builder didn't compact the base enough, cause it's just a gate. Contractors rarely properly compact for gates, garden walls and fences.

But, even if it did, wouldn't you take a 14,000:20 bet on the $20 bracket side? I'd take that bet even if it was built in a swamp.