gk7ncklxlts99w1 Videos online suggest all sorts of things. As just one example, many of them carefully instruct viewers to enable USB debugging as a key step to installing GrapheneOS, though there is no requirement for doing that.
Based on one's threat model, it may or may not be useful to do the OEM-unlock "check-in" step anonymously. It is absolutely not a requirement for installing GrapheneOS. Skipping that cloak-and-dagger step, for the large majority of users, does not defeat the purpose of GrapheneOS, etc.
Note that anybody using an eSIM is sharing their IMEI with code written by Google that must have Internet access. So being careful to anonymously OEM-unlock a device, followed by installing an eSIM on that device, seems of dubious utility.