I'm also interested in this. I've listened to some of his stuff but not all of it. Is it because he theorizes the lore of Halo by possibly giving away campaign details that may happen in future halos?
It's more the fact that 90% of the videos he puts out are nothing but speculation and conjecture. He doesn't deal so much in solid facts, and a lot of the mis-informed arguments started on other discussion forums are usually as a direct result of taking his speculation as fact. Admittedly, some of his lore speculation can be quite interesting, but that's unfortunately as far as it goes, and if you're looking for actual information on anything it might be better either going to the Waypoint forums, or hunting around for other official information releases by trusted media outlets. Anything that's not officially endorsed by 343i themselves is to be treated as speculation, and should be considered with a healthy dose of salt.