Yeah Palace 2 started filming recently. This is for the TV series. I haven't heard too much about the movie version of Palace which is the one Ming Dao is attached to. The movie version's General Nian will be completely different from the series so it's better to treat it as another time travel related story that happens to share the franchise name.

I really do hope Yu Zheng and Feng Shao Feng are ok since that'll affect the writing but I haven't heard any news about it. We'll see.