Dpreview interviewed Sigma chief Kazuto Yamaki. When asked if he “still see a healthy market for Micro Four Thirds” his answer was:
Yes, I think Micro Four Thirds is well accepted by filmmakers, and our 16mm is really popular among M43 users. People who need a compact system still love Micro Four Thirds.
And about their DC DN lenses he also said this:
Actually, demand for those lenses keeps growing. It’s really surprising. In terms of units, they’re the top seller for Sigma right now. It’s a surprise because in general the market for APS-C cameras and lenses is declining. But sales of those three DC DN lenses keep growing. Most of the sales are for Sony E-mount and Micro Four Thirds [versions], and in peak seasons sometimes we actually can’t keep up with demand.
That’s good to hear :)