There is possible proof that chalav stam is mutar not only bshas hadchak.
Right. One of the main teshuvas that is used as proof that chalav stam is mutar only bshas hadchak (dire circumstances) is YD 4:5 but that teshuva seems to be talking of a specific case in a specific circumstance, a community (Toronto) was thinking of switching to chalav stam after keeping chalav yisrael and Rav Moshe tz”l wrote that you shouldn’t do it unless it is bshas hadchak. How does that compare to other cities that were keeping chalav stam before Rav Moshe tz”l gave his heter.