It was back in 2013 that visionary anime director Hayao Miyazaki (Nausicaä of the Valley of the Wind, Princess Mononoke, Totoro) announced he would be retiring from feature film development. Shortly thereafter in 2014, Studio Ghibli followed suit and said it would take a "brief pause" after Miyazaki's retirement. Now it seems that the lights have come back on again at Ghibli and Miyazaki is in full pre-production for a new feature, slated for release in 2019, just ahead of the Tokyo 2020 Olympics. It turns out not only that the doors are re-opening, but that there's been a full hiring push going on over the past few months.
First reported by the French Miyazaki fan website Buta Connection, Ghibli's producer Toshio Suzuki had announced they had re-opened its production department with a small opening ceremony back on July 3rd. Miyazaki brought together his collaborators to talk to them about the project. They've been actively recruiting new design staff, and the hiring round was completed by late July. Now they'll have a brief break before all of the new hires go into full ramp-up mode in October and undergo six months of training before transitioning into the main production pipeline.
Particulars of the new film are still unknown; there had been some speculation that a full-sized version of Boro the Caterpillar might be in the future. The original version of Boro was intended only as a short for the Ghibli Museum, but Miyazaki has expressed that he hoped it might be expanded into a full film, as he wasn't happy within the confines of such a short story. Boro's story is described as:
"A story of a tiny, hairy caterpillar, so tiny that it may be easily squished between your fingers."