It's not uncommon for organisations to be late with renewing their domains and you probably don't want to send false alarms.
This was not a false alarm.
And yes, many scammers out there send postcards to businesses offering to assist for $1,000 on the renewals - and many people pay. So people do send out "alerts" the way you ask - most commonly exploitive and at least I give the advice to ignore ALL such renewal alerts. If you are telling people to respond to those you are sending people down scam ally.
DNS stops resolving because the domain is pending deletion. At that point it's not a renewal, it's a restore (which costs a lot more money). Refer to the brown "Domain no longer in zone" section of ICANN's lifecycle chart: http://archive.icann.org/en/registrars/gtld-lifecycle.jpg If people are actually regularly using restores instead of renews then they're unnecessarily throwing away lots of money.
> I've seen govt agencies use this as their reminder to renew.
What TLDs were these government agencies using? gTLDs have uniform policies but ccTLDs and special purpose TLDs like .gov do not (and you cannot generalize your experience there to gTLDs). But the expired nameserver domain registration under discussion in this article is a .com, which is a gTLD, so it goes through the standard lifecycle of 30 day redemption grace period + 5 day pending delete period, and during these its DNS is yanked.
Source: I've been in the domains industry for 7 years and run 44 TLDs.
As to govt agencies - sure, many use .org and .com domains routinely. These do not get special treatment - and I do generalize my experience from .com and .org to these govt run websites without hesitation.
Despite ideas - just because a public agency is using these domains does not make them magic.
to pick two domains within 10 seconds.
I'm going to stop here. Despite your claims that folks don't go into pending deletion - they do. I am responding to top comment - people fail to renew their domains on time routinely. I've seen it happen with some surprise in govt agencies (ie, someone in a dept spins up a website, and renews when someone complains its not working and they get permission to spend the money to renew - which is not instantaneous even for small purchases) as well.
All my points stand and I remain unconvinced by your claims that these govt agency websites can't expire (they do routinely), that pending deletion is a black swan event (it is not) or that folks don't fail to renew on a timely basis (they do frequently).