Yes, SPN had so much meta! There were great discussion posts back in the early seasons. I haven't seen much discussion related to any new fandoms, but I wonder if that's more to do with the fact that shows come out all at once instead of week by week. That format gave me more time to reflect and also read meta posts.

I just got into Merlin last year, so I tried googling and browsing LJ tags and I've been able to find only a few meta posts. Is your AO3 name the same as your DW name? Feel free to link me and I'll check out your posts! I'm currently rewatching Season three so that may inspire me to write and reflect more this month.