It appears the reload footage function is not working properly in AE CC2015 (2015.0.1).
I had a bunch of png sequences that were re-rendered overnight. Basically, all images just got just a few pixel wider, and nothing else. Files had been overwritten directly at the same location, and thus I expected AE to simply reload the footage. However, even if the file width appeared to be updated, the content wasn't. For instance, the alpha channel was missing pixels on each side. Strangely, the footage was missing pixels on one side only in the media viewer panel and appeared moved to one side. In file explorer, the actual media was pixel perfect. Tried to purge memory, reload footage again, checked location, etc. Only "replacing" the media did work in the end. But with several sequences to update, process looked quite time consuming.
Re-opened the same AE document in AE CC 2014, and media appeared perfectly. Save and re-opened in CC2015, and all was fixed.
This looks like a bug to me! Any thoughts on what could have happened?