I would be interested to see if there are a significant number of people who
1) only read the first post and never post in the thread
2) only use neogaf as their sole source of anime information
For me, it's not about being welcoming or not. I've always seen the OP as an art project for whoever wants to take the time to make it. It's an expression of creativity that introduces the thread but is never really talked about after the day it goes up.
I can only speak from personal experience, but I lurked AnimeGAF for over a year before my account was approved and during that time, it actually was my sole resource for news and impressions.I frequently referred to the OP because, at the time, it was more informational (and easier on the eyes) than the standard seasonal chart that was floated around AnimeSuki and elsewhere. Of course, Community didn't exist ca.2011 and I imagine that the OP concept was originally geared toward a broader reading audience than we currently enjoy.
I am long since proactive enough in researching upcoming series that I don't rely on the OP, but it can be an overwhelming task if you're just reaching the stage where you want to branch out into less mainstream content.
I'm not as concerned with optimizing the OP for perfect accessibility as I am the suggestion that it should be actively inaccessible because lurkers don't "deserve" complete information if they don't want to (or can't) interact with the thread.