I don't think Caitlin is dated at all. It's a "modern classic".
Definite 90s name, but I still think it's wearable on a baby of today
I actually really love Caitlin (this spelling only). Yeah, I know quite a few Caitlins/Kaitlyns/Kaitlins/Katelyns from the 90s--I remember in a music history course I took in college, we had our names printed on our desks, and there must have been 10 Kaitlyns/Kaits/Katies/etc. But in day-to-day living, I rarely come across any. I have one coworker, Kaitlin, and my mom's former coworker has a little girl (probably around 4 now) whose name is Caitlin Rebecca, I believe. I still think its very pretty. I feel like it was overused in the 90s, but it feels no more dated than Rachel, and you can see how much I love that. :)
I would actually love to hear the Irish pronunciation, but I think that's sort of unrealistic to hope for that in America, haha. But the Irish pronunciation makes Caitlin fresh again, imo. :)
I don't know anyone who has it spelled the same. I know a Caitlyn, Kaitlyn, Kaitlin, and Katelyn, as a late '90 baby. I've seen Catelynne and Kaytlin in older yearbooks as well. I do like Caitlin but I know so many that I know it is going to be a pain to spell, so it would be wise to go with the more elegant, similar sounding, uncommon Catalina/Katalina.
To me, Caitlin and its many spellings aren't as much dated as overused and trendy (with the -lyn ending).
The original -- Caitlin -- feels quite like a modern classic, but its spelling variations all feel dated to me.