The makers of Clayoo, RhinoGold, and a few other tools (TDM Solutions) were bought out by Stuller. that previously bought up Gemvision, the makers of Matrix. They are primarily focused around jewelry.
It remains to be seen what they choose to do.
T-Splines was bought up by Autodesk several years ago and has scattered the developers they kept across Autodesk. Don’t expect there to be any future versions of T-Splines for Rhino. Autodesk has never been in the business of doing anything to help or extend products they see as competitors.
We have started work on a long-term subdivision modeling project that should eventually bring some of these tools into native Rhino and possibly into the Rhino SDK for third-party developers. Best wild guess time-frame would be Rhino V7.