According to our Asia source, Yongnuo is going to announce their first FE lens in next several days, probably on China P&E Show on April 12-15, 2019. This new lens is rumored to be Yongnuo FE 50mm f/1.8 AF lens, price will be around $100. The current price for Yongnuo YN 50mm f/1.8 Lens for Canon EF/Nikon F mount lenses are around $50 in US.
dpreview has interviewed Sony Kenji Tanaka, VP and Senior General Manager at CP+ 2019. Kenji Tanaka said that it is easy to add 4K/60p, 10-bit 4:2:2 to Sony a7S III, but he want to create something that goes beyond the expectations of our customers. And he also said that a7S like APS-C mirrorless camera is possible.
At CP+ 2019, French website Phototrend has interviewed with Tamron executives confirmed that they will make the telephoto zoom FE lens next. Tamron will also consider prime FE lenses for Sony full frame mirrorless cameras in near future.