The article you quoted does an admirable job of explaining the license controversy
surrounding DD-WRT.
It remarks that :
- The DD-WRT source may not be the latest version and may
lag behind the released binaries and this is sometimes done on purpose.
- DD-WRT itself may sell specialized versions whose source is not released.
- Specific adaptations of DD-WRT by other developers may be legally released
as closed or with other licenses (this does not conflict with the GPL).
So the answer to your question about versions posted on DD-WRT website and forums,
is that this totally depends on the publisher who is at a total liberty
to publish none or part of his source under the license of his choice.
However, if the developer publishes his code without a separate license
and still under the name of DD-WRT,
then I believe that the original license holds - which is the GPL.