My world is locked in hard mode and I never use commands or mods. I fight often through the night in caves and outside in a variety of regional difficulties from the highest to the lowest. Usually, I fight around my main base which has had the highest regional difficulty for years of real time. However, my I describe my play style as "distant adventurer," so I fight in quite an expansive set of circumstances.
Tonight, it dawned on me that I don't recall the last time I saw a spider jockey. Clear back in PCMC 1.8.x, maybe? So, late 2015? Unless I'm forgetting instances.
I looked through the bug tracker but admittedly, I'm not very good at navigating that site. My Google-Fu didn't reveal any other issues, either.
I understand they are rather rare, 1% of spiders, but I've killed several hundred spiders and I've seen mobs in full diamond armor since I recall last seeing a jockey.