In fact Alpha 4 was released on the 12th of November and Alpha 4.1 was released on the 15th. In effect the Alpha release process was a complete failure, some people, including Haiku's release manager experienced the faults that later required Alpha 4 to be replaced during the brief testing window for the Alpha 4 release but there was no real "release candidate" programme and the problems were brushed aside as probably specific to an individual machine.
which arguably makes the organisational failure more significant
“FreeBSD drivers can be easily recompiled to support Haiku”
In fact Haiku has a rather limited framework which is just about enough for most FreeBSD WiFi drivers for PCI hardware (ie no USB). If there's a FreeBSD driver for your hardware but it's not a PCI device, or it isn't a WiFI network chip, you're probably somewhat out of luck. If the driver you need exists but isn't "released" for FreeBSD then it won't make its way into Haiku. So for new WiFi chipsets you have first wait for a FreeBSD driver to be developed, then for a new FreeBSD release to feature that driver, then for a Haiku maintainer to import the driver, then a new Haiku release.
For audio (PCM) hardware Haiku have a sprinkling of their own drivers, some working, some incomplete, and they have a port of the OpenSound System's collection of PCI drivers (again no USB). The two are incompatible though.
One fascinating thing about this article is that it seems to be largely based on interviewing Ryan Leavengood, a sometime developer of Haiku. Whereas interviewing Linus Torvalds about the Linux kernel would give you some confidence that you were getting answers from "the horse's mouth" the same cannot be said for Ryan and Haiku. The last time LWN linked an article written by Ryan he was predicting this same Alpha 4 release for April, in August Ryan became Release Manager for Alpha 4, the release continued to slip and in October Alexander von Gluck IV took up the reins and eventually got Alpha 4 out the door.