There are several "cloudelastic" LVS service defs starting around:
They all share a hostname but use different ports.
The icinga check part ends up creating just 1/N checks (I think because they share a hostname), and the host definition for it uses icinga1001's IP address instead of the service IP (which luckily fails because of the odd port number, otherwise we might've assumed it was ok if it was polling icinga1001's 443):
https://icinga.wikimedia.org/cgi-bin/icinga/status.cgi?host=cloudelastic.wikimedia.org
I have no idea what's going on with this and I'm giving up for the day, but maybe someone else can figure it out!