It’s interesting for sure!

I think MJ has famously said to the effect that you can’t force good music. It takes time and it’s important to work on whatever feels important at the time. What speaks the strongest to you. Otherwise it’s mechanical work with less real emotion.
There’s good reason his released music is very authentic and representative of his mindset at each time. But also practical reasons things were released had much to do with team work and how far along producers were at any given time. And whether others on his team were really attuned to his vision…
He seemed to work ”by epiphany”, often calling people in the middle of the night with ideas on his ongoing work…
Being the sole overseer of (over the years) many hundreds of songs and ideas is quite a task, especially for OCD folks like MJ.
And the old ideas had to compete with his ongoing creativity which was at times extremely productive.
I think the song lists found after his death show how structured he knew he had to be to get anything done.
Still, when something just took over his system, like Billie Jean which didn’t need too many embellishments, it could be perfected it in quite a short time.
But imagine ideas of that calibre that weren’t released for years… it makes sense that they would continue to speak strongly
Like releasing little suzy in the 90s
Some of the most heartfelt music grows slowly