No, it's not canceled from what I can tell. Currently, build 3 for the patreons was released 14 days ago, and if it was actually cancelled I would expect more communication on something that big for a project.
Though it is worrying that it's been a while with no updates. Moreover, the only mention for public release was in a now-deleted public Patreon post around 18 days ago on May 5.
It said "The public version of the third build will be released sometime in the first half of this month" (I was excited and screenshotted it), which is (obviously) now way past the first half. But seeing that it's deleted, my best guess now would be around June 8, assuming they want to wait a whole month after the Patreon release.