Meanwhile...

> they would not notice within a 24h period or even a 48h period since there is this little thing called weekends

Fine, make it 1 or 2 _work_ days. For vacations you should get coverage. If you are the only maintainer, then the project has "a bigger problem".

> and also people are not generally in the habit of checking their own package releases constantly.

Even if I'm very busy with other things and flooded with email as usual, I will 100% notice a "New X release!" notification if X is software I maintain! It's a rare and important enough event. If it's too routine, then something is probably wrong with X's release lifecycle (which is obviously a very important parameter in this entire discussion).