schweizer Ok, now I'm not absolutely sure anymore. When I first toggled eSIM support on in GrapheneOS I did this for installing an eSIM from a provider. So maybe the Skylo eSIM just appears after that installation. The eSIM support is an proprietary app/function from Google. While installation it connects to an eSIM-management service to download the eSIM profile, check and confirm the status of the SIM. Most providers use
.prod.ondemandconnectivity.com (don't know, if there are others). Also after installing, if you want to disable or delete an eSIM on your phone is a connection to that service necessary, so your provider knows the status on a specific device.
Anyway, so I think beside installing a provider eSIM a query to that service seems to be initiated with the result "it's a supported Google Pixel and the Skylo eSIM hast to be available". But now I'm not sure anymore, if the profile was preinstalled and only made available/visible by that connection or downloaded then. But what I can confirm, it's provider independent, it always appeared on a 9th series Pixel after the first installing of an eSIM.
And I'm also not sure if such an installing activity is necessary. Some people reported, when having eSIM support toggle on the whole time, it frequently connects to the named services. (Although that's not really necessary, because eSIMs work also with that service toggled off fine, it's only needed for installing, de-/activatin or deleting an eSIM.) So if anyone want's to check the behavior on maybe a test device (which should principally support that satellite SOS feature) could toggle eSIM support on without ever installing one and wait if Skylo eSIM will appear after a couple of time.