The sad news are that the creation of animations is one of the many features missing in Prime compared to Mathcad 15 and below.
I don't know if PTC plans to add a comparable feature in future versions.
The same goes e.g. for scripted components.
Primehasa fewselectiveadvantages like being able to solve DEs numerically using units and (much) better handling of manual input of matrices (but then scrolling in large matrices is inferiour and awkward) but these don't compensate for the missing features and the many drawbacks Prime has, like awfully slow performance, slow starting, slow UI reaction, uncomfortable and cumbersome UI which slows down the workflow, etc.
So if you can decide it your own what version you use you are lucky as you can stay with MC15. Still too soon to change IMHO.