yeah, Lord-Relictor has only ever been in the main starter box or the Thunder and Blood starter set.
There are quite a few stormcast things missing though. Knight-Vexillor, Knight-Questor are no longer on the website. Yet, Knight-Questor is this year's Golden Daemon 'Eavy Metal paint masters category miniature.
I haven't checked to see what else might be missing.
There is a rumour engine pic that shows a Stormcast shoulder that hasn't been released, so either it's just an incorrect way of noting stock shortage, which usually just says temporary, or they've been to be re-boxed, or they may actually be gone for good. There's no real way of knowing