Answered
Determine if text layers need updating
Ignoring the "some text layers might need to be updated..." message ...
Is there a scriptable way of determining if said text layer has the triangle warning icon??

(text layer needs updating warning icon)
Kinda like this:
if (theLayer.kind == "LayerKind.TEXT")
{
if (theLayer.textItem.feelingABitSleepyAndNeedsToBeUpdated == true)
{
theLayer.textItem.refresh();
}
}
Assuming this is only caused by old file created in prevouos versions of Photoshop.