Jannies are very inconsistent and some are more sensitive to certain things than others. Pic related drew a warning, which is ridiculous but apparently that particular janny was simping for old women. Doubt the mods really care about jannies going overboard. IIRC, jannies can't delete entire threads so it would have been a mod who did it, but I don't know that for sure.
If it wasn't deleted for slurs, maybe it was an error due to several other faux cfb threads being started and deleted around the same time. Think one was about the Canadian Football League and the other was some weird muttering about FCS.
Generally I look at moderation policies here as being like weather. Sometimes it's good, sometimes it's bad, and there's not all that much you can do about it.