Apparently pro tools came out in 1989, makes me think this may or may not be true. This article has some info about the mixture of analog and digital tools use to record:

> The main event was a brand-new mixing console called the Harrison Series 10, which was the first analog console to feature a digital control surface, with full automation of all parameters. Jimmy Jam and Terry Lewis were the first studio to have it, according to Jam. This meant that they could cut down the time it took to switch songs to about 10 minutes because complex mixes now required little-to-no cross-patching.

https://reverb.com/news/the-making-of-janet-jacksons-rhythm-...