Imagineering is inherently project based work, and Imagineers are usually let go when not assigned to a new project. For Galaxy's Edge, WDI had entire office buildings of designers and engineers setup backstage at Disneyland. They were there for the design and construction, and by May of 2019, before it even opened, they were all cleared out.
Shouldn't read too much into it, as far as the reception to Galaxy's Edge goes. They fired the creative team that built Tokyo Disney Sea too.
All the creative folks that worked on Galaxy's Edge are still there. Trowbridge, Kalama, Beatty, and Kerrison. They're all still working on Star Wars projects. If I am remembering correctly, Trowbridge is actually the portfolio owner for all of Disneyland Park, and just recently showed up during an in-house 65th Anniversary presentation.