On thinking about the reasons this may be something at least slightly more than training on the task is the richness with which language is filled with spatial metaphors even in basic language not by laymen considered metaphor outside the field of linguistics proper, in which concepts eg Lakoff's analysis in "Metaphors we Live By and others are simply part of the field, (though unsurprisingly, among the HN crowd I've occasionally seen it brought up)

The amount of money you have in the bank may often "increase" or "decrease" but it also goes up and down, spatial. Concepts can be adjacent to each, orthogonal. Plenty more.

So, as models utilize weight more densely with more complex strategies learned during training the patterns & structure of these metaphors might also be deepened. Hmmm... another thing to add to the heap of future project-- trace down the geometry of activations in older/newer models of similar size with the same prompts containing such metaphors, or these pelican prompts, test the idea so it isn't just arm chair speculation.