Nisht,
There is a machlokes haposkim about whether or not Yoshon applies m’doiraisa in chutz l’aretz. While m’ikkar hadin we pasken that it is muttar, to be choshesh for the machmir shitta in an issur d’Oraisa is certainly commendable.
Chalav Yisroel is itself an issur d’rabbanan. R’Moshe held that m’ikkar haDin american milk is considered Chalav Yisroel based on an “anan sehadi.” R’Moshe held however that there were grounds to be machmir and therefore it would be commendable for a person to drink only milk directly supervised by a Jew (b’toras chumra).
If a person wants to take on a new chumra (for an extra zchus), it makes more sense to choose the keeping of Yoshon even in Chutz L’aretz, then to choose being machmir for a Chalav Yisrael label on your milk.