Thus Spoke Rohan Kishibe is a spinoff of JoJo Part 4: Diamond is Unbreakable featuring the aforementioned character in solo misadventures. David Production animated only a few of the spinoff's episodes for OVA release last 2018-2020. NHK will follow this pattern.
Issei Takahashi will portray the stand-using novelist Rohan Kishibe. For those who watched Kyoryu Sentai Zyuranger, he's Kai, Bandora's son. Issei was also in Shin Godzilla as one of the many federal workers who worked with Yaguchi in stopping Godzilla.
To note, there was a JoJo Part 4 live-action movie, but only the 1st movie was released. If this is the plan to restart this shindig, I'm not holding my breath.