The logic of that statement is that, at some point in time, "something" spontaneously burst from literally nothing. It also would require that "time" does not "exist" in the same way that "things" exist -- but General Relativity seems to tell us that that's not the case.
Or perhaps you mean that the "form" of existence changes with time?
I'm not convinced that using the term "existence" apart from saying that something in particular exists makes any sense.
I can accept that.