The officially-licensed Mega Man: The Wily Wars reproduction cartridge from Retro-Bit was announced in August 2019 with an intended Q1 2020 launch. We haven't heard much from the project since then. Granted, we're living in unprecedented times. The ongoing pandemic has affected it. That said, if you were concerned the project was outright scrapped, I come bearing good news.
Retro-Bit has confirmed that The Wily Wars reproduction cartridge remains in active development with "a lot of action happening behind the scenes" as they prepare for release. More news will be delivered later this year, which could very well entail a release date.
For the uninitiated, Retro-Bit are not only developing the reproduction cartridge but a Collector's Edition that includes bonus goods, too. These include limited edition packaging, mini Mega Man, Elect Man and Cut Man figures (the later is transparent!) and other unannounced odds and ends. You can get an idea of what might be included from Retro-Bit's past Collector's Edition offerings here. They spare no expense!
And that, my friends, is all there is to say on this front for now. We'll keep you posted as more info becomes available!