Panasonic has filed a new patent P2019-15827A for an 18mm f/4 mirrorless lens designed for APS-C based cameras. Could it be that Panasonic is working on a new mirrorless camera with L-mount?
Leica already has two APS-C L-mount mirrorless cameras (Leica TL2 and Leica CL) and a few lenses.
In an interview with Dpreview a few months ago Sigma confirmed their plans to develop APS-C lenses for L-mount, while Panasonic said that they will not make APS-C lenses for L-mount:
"Do Sigma and Panasonic see the L mount as an APS-C mount as well? Are you planning on developing APS-C lenses for L?
Sigma: Yes, we have a plan to develop APS-C lenses for L mount, but the main focus is full-frame.
Panasonic: No. We will only develop [L mount products] for full-frame sensors."
Details from the Panasonic 18mm f/4 APS-C lens patent: