I can assure you that they do the same thing with flagship phones, especially carrier versions of the phones -- speaking from first hand experience. I have seen notifications from apps I have never heard of multiple times.

That's what I have been thinking recently -- given that Samsung is quietly doing these shady things with my phone, and other annoyances like Samsung forcing Galaxy AI on me (try selecting some texts in a browser or webview) which cannot be uninstalled and the terrible Samsung Pay interface, I am questioning my device choice every day.