In Unreal, and most C++ implementations, as well as many other programming languages, there is an automatic initialization of all standard variables when they are created. This, by proxy, tends to extend to full objects because at their deepest level, virtually every data structure is created from a combination of the standard variable types…
That being said…
It is unwise to -=rely=- on that programming practice. My first computer instructor (back in the 80s) had a large sign over the chalk board that said “Assume Nothing.”. Of course, back in the 80s, there were virtually NO programming languages that initialized variables.
Callling Reset() at the start is, in fact, completely and totally unneccessary in this environment, because, you’re right, in this environment, everything is already reset. But… best practices say you reset -=anyways=- because tomorrow you might be programming in an old version of Pascal that does NOT.