Actually "Playboy Mansion" is brilliant- one of the best songs on the album. It's in my personal top 10-20 of all time.
Don't get thrown off by the pop culture references- just understand them and the larger point that u2 was trying to make.
And this is not just me talking- random u2 fan.
This song was studied in at least 1 university Religion class. I know because my daughter was in the class.
And this is at one of the better universities in the southeast US so there are probably others.
If you are wondering about the larger point of the song- it is that consumerism has become our religion.
Bono brilliantly uses many religious terms in the song. (Mystery, truth, gifts, Obsession meaning zealotry, Confession, pool, and yes Mansion.)
Then in the final stanza he parallels heaven (no sorrow, no shame) with the playboy mansion.
So yeah- it's not about Michael Jackson that much- except for his status of being worshipped.
I think he needed something to rhyme with "mystery" and MJ's latest album fit the bill.