No. But if it’s the shitta held by Reuven in our OP, that’s why Shimon is buying him Cholov Yisroel, davka.
It’s unlikely that that’s the shittah referred to in the OP.
Even those who hold by Rav Moshe’s shitta, Rav Moshe paskens that a Baal Nefesh should only eat Cholov Yisroel. He doesn’t pasken that a Baal Nefesh should only eat CY when home. So a Baal Nefesh should only eat CY anywhere, even when a guest, according to Rav Moshe.
That’s a twisted bit of logic.