Thanks Steve, also interesting. You might be right about this not being an Adobe thing, as the files in question, the ones showing up with the new dates, are ones that I haven't touched, even looked at, in years. Tho, on the other hand, I'm not sure what exactly the OS would be doing with those files either. I can see, by using a Windows file manager/explorer, that Windows has several 'dates' attached to each file. Using one of the problematic files, I can see something called 'Date' with 9/19/2009 showing - probably the date taken. Then, 'Date modified' showing, also with 9/19/2009. And finally, 'Date Created', this one with the 3/1/2014 showing. This is using the OS, outside any Adobe product. I'm not clear if PS CC is just using these OS dates and not assigning any of it's own? That would make sense, and would fit your suggestion that somehow the OS is responsible.
In any case, it seems to have stopped. No more files are showing up as misdated. For the dozen or so that have been 'changed', I might just try to figure out how to change the OS 'created' date manually and change them back. It's been years since I've wasted days trying to fool with Windows, maybe I should give it a try just for old times sake.
Thanks for the help