
The Panasonic LUMIX G 20mm f/1.7 II ASPH lens is already listed as discontinued in Japan:

OM System announced a new TG-7 INDUSTRY camera kit designed for microscopes based on the existing TG-7 model: Pre-orders Additional information Product page Press release OM System continues to recycle old products: today we have a “new” TG-7 camera kit designed for microscopes