In brief: It looks like China has the coronavirus outbreak under control in the region, but Apple's supply chain is still moving slower than planned to build the new iPhone 12. According to industry insiders, the company still has at least one month before it can begin assembly of the new phones, but otherwise it looks like the original launch window is still a realistic target.
Back in November 2019, when the coronavirus wasn't on anyone's radar, Apple was telling suppliers to expect over 100 million orders of its upcoming 5G-capable iPhone 12. That started looking much less realistic earlier this month in the context of a significant slowdown of production and delays in the supply chain for essential components.
Still, both Apple and analysts have maintained that there's no reason to believe that the company will have to delay the launch of any of the products slated for this year. And, sure enough, Apple recently launched an updated version of the Retina MacBook Air with a scissor keyboard, with the MacBook Pro expected to be one of the big highlights of the online-only WWDC in June.

The company also refreshed the iPad Pro with a better camera system and a new Magic Keyboard accessory that makes it look like a strong alternative to Microsoft's Surface Pro. And according to a new report from Bloomberg, the release of the iPhone 12 is still on track for this fall.
Mass production of the new 5G phones from Apple is slated to begin in May at the earliest, as Bloomberg says industry insiders are still seeing a slow pace of component shipments for the assembly process. For instance, Apple relies on Broadcom for wireless chips as part of a recent $15 billion deal, but the silicon giant has recently said that it's expecting a significant impact on its business through the second half of this year.
Apple seems optimistic about the situation, especially if you look at its decision to reopen its physical stores in China. CEO Tim Cook also said earlier this month that the lower production rate observed at Foxconn is a "temporary condition."