Single lay service is not a widely accepted vocation in the west, but is piously included in our current time because of the issue of homosexuality. The only reason this juxtapositioning is necessary is because the priesthood is likewise included among the pious list of vocations, which had to be distinguished from religious life when it made its resurgence in popular culture, which now must be distinguished from the homosexual “marriage” alternative.
I think the vocabulary will become more nuanced in time. We already see the west explaining that the priesthood must be confirmed by the church. That’s not a vocation, that’s a ministry. The vocation underlying all these that they’re needing to discern is celibacy, but the west is leaving this vague and undefined because none of the pious traditions are doing damage. They’re letting the people figure out the nuances, just like they did with the infants in limbo idea that was commonly cited but ultimately rejected.
The east is more direct in defining two vocations: celibacy or marriage. Everything else flows from one of those two states and ministries like the priesthood are called out of those states in order to serve the church. All people are called to living in a community that supports the fidelity to one’s vocation as that vocation is the vehicle through which a person grows in God. So the idea of being a single lay person is included under the broad umbrella of celibacy, but that person is just like all the others in that he will need a community to attach himself to to help build up and support the vocation.