I wonder about this. I don't know in the lore how long Celebrimbor survives, but I think Sauron and Feanor both trained under [smith Valar whose name I've forgotten], so maybe he doesn't need Celebrimbor for the One.
I was niggling in the other thread about how I disliked that Celebrimbor has no one really close to him who is with him in Eregion and is affected by Sauron's manipulations. I get that Sauron is taking advantage of that lack of support system, but why was it there in the first place? Has the show established that he has self-isolated? I'm just curious if I've missed something. We know he is kind of obsessed with making something "truly great", which Sauron is also playing on, and that could lend itself to isolating, too - although really he should be reaching out to learn even more.
Anyway, he's a fascinating character, I like what the show has done with him, and Charles Edwards has done a great job of playing someone who seems harmless and well-intentioned, but who has had that turned against him.