Some have objected to the word "universal" - arguing instead for "generalized". These objections are not technically correct, I believe - though "generalized" is also a reasonable term.
However, the term "Darwinism" also has some problems. In science, it's normally the idea, not the man, that is celebrated. "Darwinism" sounds too much like a religion consisting of followers of Darwin. Some object that evolutionary theory has moved on since Darwin's era, and the term "Darwinism" fails to recognize this properly. Neo-Darwinism has been tried - but alas, used dogmatically - and it isn't clear whether the term is still usable.
The main problem I see with "population dynamics" is the term "population". For many, this term has a fairly specific technical meaning - which is not really appropriate for the topic. However, I think that this technical meaning is narrow and bad - and that we should just recycle this term to refer to any-old collection of things.
The term "population dynamics" has also been used in a limited way - to refer mainly to births and deaths. I don't see this usage as much of a problem - science can't allow "population dynamics" to mean that.