There are a lot of loaded terms in the description in this question.
There are no easy answers to compatibility. My own packages tend to be very stable and backward compatible but they also have bug reports that have been open for 20 years as they can't really be fixed in a compatible way. Not everyone would say that is better. As @percusse says in his answer it's the package author's call, and in any case an existing document can always use the current package. tabutabu
has some good ideas but it reuses the syntax of the standard arrayarray
package in an incompatible way, which is an unfortunate choice, but neither that, nor the fact that the package author indicated he had changes planned, makes the package "dangerous".