There’s nothing to excuse. Telling someone something personal on your own timeline is not lying by omission. Neither is lying by omission “lying” at all. You’re not entitled to all personal details of anybody you date.

He did tell her. She did make an informed decision. Why are you pretending otherwise? And where do you get off pretending you speak for “most rational people” in the first place.

If you were to say you’d never disclosed something personal to a partner at a time of your own choosing, I’d call you a liar. And if you’d say that you had, I’d say then you’d need to go back and examine your points 1 and 2 above more honestly or else admit you’re a hypocrite. Which is it?