Think it is a choice by the developer.
But Project-GC has similar tools here https://project-gc.com/Statistics/LonelyCaches and here https://project-gc.com/Statistics/DaysSinceLastFound. Maybe not as nicely presented as the site in the OP, but can be used for all the countries.
I wouldn’t do any maintenance, it’s up to the CO to care for the cache. And throwdowns are generally frowned upon. But do log a Need Maintenance log so the CO gets informed that there may be an issue with it. As a CO myself this is what I prefer.
The CO may be inactive and the cache is abandoned, but then the spot will open up again and someone can place a new happy cache in it’s place.
Ohh, nice!!
You better make a calendar event or something for February 29 so you don’t miss. I would be devastated if I had to wait for four years till the next chance