I only superficially agree with this take because of the many cultural implications of marriage. E.G. Kids, housing, money. Decisions that
may carry serious implications and cannot easily be undone should not be rushed into.
With that said, marriage is not a prerequisite to any of these potentially problematic aspects of relationships, which makes the entire idea of the restriction-by-association a bit silly. Especially because it is not placed on 'new' relationships, merely on the the transferring of relationship statuses in a very particular manner.
I think marriage itself is a bit of an antiquated institution that needs a modern re-work to better fit it to societal needs.
I fully support the current marginal waiting periods for marriage licenses because I feel like this minor barrier does not meaningfully inconvenience the vast majority but may prevent cases of abuse or caprice.
TL:DR - Liberalism and guardrails.