I don't want to minimize your friend's situation. But, a spousal visa is very different from being a permanent resident (maybe I am misunderstanding). If he got it through marrying a US citizen, there's a 3-year wait for naturalization and otherwise it's a 5-year wait.
Naturalization never required leaving the country, at least in my experience but things might have changed.
You're right, I fixed the wording. I don't know all the details, but I do think it's a recent change. They've been married for almost ten years. His wife and child are US born.
Trump ended in-country processing and now requires almost all greencard applicants to go to a consulate abroad. My friend and his wife were surprised and nervous when they were told he'd have to leave due to this new requirement (rightfully so, in retrospect).
Confused as well - spousal visa gives them a green card, does it not? What is there to wait for? Are they postponing green card renewal as well?