So the information that is cited is incorrect?
Really?
From the Libertarians:
Libertarianism is a moral and political philosophy that argues in favor of a strong presumption of letting people engage freely in mutually consensual activity and on minimizing coercion in society. In the modern political context, libertarians generally focus on government-enforced and government-facilitated coercion.
The right to migrate can be considered a corollary of the libertarian view that people should be free to do what they please (individually or collectively) unless it violates the rights of others.
Libertarians’ view of obligations to strangers has two core premises. First, no obligations to strangers beyond respecting their rights. Second, a very strong obligation to respect their rights. Together, these premises argue in favor of not letting concerns about harms to fellow nationals be a justification for opposing free migration.
Although libertarian theory does not really offer a case against free migration, libertarians have argued against free migration on consequentialist grounds (in terms of the detrimental effects that an open borders policy would have on moving towards or maintaining a libertarian society) as well as via the anarcho-capitalist counterfactual.
Even many libertarians who do support freer migration do not consider freedom of migration a high-priority issue.
What the Libertarians really think about open boarders