One can easily read between the lines...
Assuming they are working with...
After racking my head about what would motivate them to give back all of the PTS this is the clear open and shut case. It is also clear that if this is the reason, those who gave PTS would clearly support rescinding the donation. I could be completely wrong.
This theory...
Mr. ghost, your analysis looks thorough and your theory seem quite reasonable. If it is true did they need to post this thread at all? I don't think so. In doing so they ran the risk of injecting speculation and uncertainty into the community, at least with the ambiguous manor they posted. As I stated earlier, there are better ways to inform the PTS donators of the refund, if that was even necessary (it probably was, even if only for courtesy).
And what harm would there be to disclose the reasons, if your theory is correct?
They could have disclosed the refund in another thread, still public, still on this forum but in a less visible location. It's just not a good example of wisdom imo, and I couple it with the lack of wisdom used with the merger post. I would like to see them get wiser, but my confidence in this area is still weak. I'm not seeing the vetting / scrutiny of potential problematic posts we were promised last month in the wake of the merger announcement.
I do have hope however, as I still trust in the principles they have publicly stated on many occasions.