They have a release policy that is not yet official according to them but I believe they already try to apply but it doesn't yet matches what they have been doing: https://wiki.netbsd.org/releasing/

quoting:

"Timeline

The release engineering team will try to meet the following timeline

    One new major branch and release per year
    One point release for the newest stable branch every other month
    One point release for the old stable branch every quarter

"

history: https://netbsd.org/releases/formal.html#history

They took 4 months instead of 2 for the next one point release since 11.0 and have released one 10.2 since last update of the release document.

Hence the work in progress statement. I am personally fine with that. They could probably do with more workforce as many projects.