ALT1053Radio has tweeted a link to their article that suggests that Matrix 4 will be filming in San Francisco in February 2020. The piece references a tweet from the San Francisco Gate and an article that appears in their paper.
The San Francisco Gate reports that the San Francisco Film Commission has confirmed to them that a major film with the working title, Project Ice Cream, will be filming in San Francisco beginning in February 2020. As previously reported, a listing in Production Weekly the week of September 5, 2019 indicated that the working title of Matrix 4 was Project Ice Cream.
Note: The December 4, 2019 issue of Production Weekly has an update on Matrix 4. Hopefully someone with a subscription will chime in with the info.