Personally, I don't think he should include either type - and there are several reasons for this.
First and foremost - the very nature of this discussion shows that they've been overdone. Everybody associates them with MJ now, so any further additions to the genre will be tired. It's become almost a self-parody that every MJ album will include a least one preachy environmental song and several media-bashing rants. In other words - it is utterly predictable.
Secondly, the standard of both genres has steadily declined with each of MJ's albums. Heal The World wasn't a patch on Man In The Mirror, and by Earth Song he was beginning to sound really preachy. Then Cry just sounded like a substandard remake of MITM, right down to the whispered outro.
Similarly - the anti-media songs declined as well. Leave Me Alone was subtle and nuanced - layered and loaded. It possessed both humour and poignancy. Each subsequent album contained increasing numbers of anti-media songs and the quality was deteriorating. Privacy was really quite embarrassing - the lyrics didn't even make sense; Princess Diana died in August - Summer, not a 'cold winter's night'.
Thirdly, each genre opens him to ridicule. There is a certain hypocrisy about a man who spent fifteen years powering an entire theme park in his back garden, largely for his own amusement, whinging at everybody else about how they're damaging the environment. Similarly, there is a certain hypocrisy about a man who feeds stories to the media about buying the elephant man's bones and sleeping in hyperbaric chambers, then starts whinging that they're all printing lies about him.
Fourthly, each album is reviewed before its release and reviews often have a strong bearing over the subsequent charting of an album. Is it really the most sensible approach to openly antagonise the very people reviewing your album, knowing that the album's profitability rests on their responses? Common sense suggests not.
Finally, you have to go back to what made the public fall in love with MJ. It was clever, succinct dance albums - uncluttered and primarily joyous. If you trace the line, the more he preached about the environment and the media, the less his albums sold.
I think the main problem is that people can't relate to anti-media songs and they're past caring about the environment. Nobody wants to hear a multi-millionaire pop megastar whinging about how dreadful his life is - it sounds patronising. Most people can't relate to it and many are irritated by it. Similarly, nobody wants to listen to a man whose spent forty years flying around the world in private jets lecturing them on how they have to recycle their plastic bags - that's patronising as well.
He should return to Off The Wall/Thriller style music - legitimate, fun, soulful... something people can enjoy and also relate to.
