I suspect that the unspoken tactic right now is to stop support for P3D because it's a pain to keep maintaining, with very few sales. It's clearly far better for FSDT financially if you go and buy everything again for MSFG, even if this is immoral. Umberto has been very active in the MSFG sub forum recently commenting on bugs and support issues, but since the P3D update a few weeks ago partially broke the boarding, there has been radio silence. I'm guessing we will we will be given an "end of P3D support" announcement in the next few weeks, or maybe it will remain unspoken. I hope I'm wrong.
It's not totally unreasonable to do this, but if that is the future then FSDT should really withdraw all FSX / P3D products from sale if they won't provide support and break them with updates that can't be rolled back. Just like PMDG's recent behaviour, it means the P3D customers who basically provided FSDT's income for years are being dropped. That's business I guess, we can't really complain as we have had a good product that has worked off and on for many years.