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My totally unsubstantiated guess from the description alone was 'I wonder if they switched to a larger package component and forgot to update the pads.' That could be described as the 'component being too large for the device' and while it might just fit, it may be borderline mechanically and electrically stable. That could also explain the added underfill. Is that possible?

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It’s certainly possible someone did a BOM substitution and didn’t due diligence on it, but I doubt it. PCB assembly houses tend to notice components that are suddenly too big for their pads because they’ll have fallout in AOI or later testing.

The underfill was likely added before full production as the result of reliability tests that showed some mechanical susceptibility of that IC.

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