Having been deeply associated with Delcam since 1994, I know this company, its products and people extremely well.
It's important to differentiate between Autodesk and Delcam here. Autodesk is a $2B publicly traded company that needs to meet projected revenue and profitably targets
The decision to exit the Dental business and the method by which the decision was announced to the public (and its own people) was a Autodesk decision. Based on Autodesk's behavior (relative to their at minimum, 50 or so acquisitions over the last 20 years),the way it was executed looks to be in classic Autodesk form.
A study in Mergers and Acquisitions theory and an knowledge of Autodesk's behavioral characteristics would lead one to believe the exit was based on the former (entirely on economics and the bottom line) and the details of the execution based on the latter.
My opinion is that Autodesk, being a publicly traded company needs to not only meet targets, but needs to make their stock attractive. With their current market capitalization being $12B and their revenue being around $2.5B, the market cap-to-revenue ratio would make Autodesk stock so overvalued many investors would stay clear.
Additionally Autodesk (like many software companies) looks to be moving in the direction of subscription and cloud based packaging/licensing. Dental applications have a significantly higher service content to them making the Dental vertical market a poor candidate for that corporate strategy to protect and realize steady, predictable growth.
So after looking at the revenue associated with the Delcam Dental product line and comparing it to the development, service, marketing, etc. costs and determining it is not a good candidate for the "New Paradigm" the decision was made to kill it.
Again, this is just my speculation, I have no inside knowledge of any kind; just one guy's thoughts. Who knows what the reasons or motivations are. Only a few know what's really going on; heck it could merely be an impulsive thing of some of the upper echelon...or not. The expression I once read: "never assume conspiracy when incompetence will do." comes to mind.
Relative to the way forward for existing DentMILL customers, I have many thoughts on this. Please contact me if interested.