For organizations it's definitely an advandtage, as it also allows for preventing data flowing to personal accounts. Right now, any employee could knowingly or unknowingly exfiltrate data, by just connecting to e.g. the personal instead of the organization's JIRA account, and there is essentially no standard way to guard against that as an organization.

That's also blind spot in normal OAuth and I was surprised to find that this was never addressed in all the years that non-MCP OAuth found adoption.