This will usually give you the right answer, but it might be an old cached version."
Is that really ever a problem? Who changes authoritative nameservers for a domain? This is by far the easiest way and the whole blog post could have just been six lines long.
The whole point of the blog posts is to explain the problem in detail, not getting some quick task done for the sake of getting it done. Just like https://jvns.ca/blog/2021/12/04/how-to-use-dig/ isn't "Use man dig" but an in-depth explanations of the features and usage.
Anyone who has just bought a domain, or anyone who is changing their hosting to a new provider.
It also relies on the registry operating an accurate and reliable whois service. I would not count on that from ccTLDs.
Edit: registrar’s whois
> I’m writing this because if you made a DNS update and it didn’t work, there are 2 options: Your authoritative nameserver doesn’t have the correct record. Your authoritative nameserver does have the correct record, but an old record is cached and you need to wait for the cache to expire
What I'm wondering is how whois data is cached. Anyone have a reference on how that works in practice?