@Jaguar,
There is, and has already been an AmigaOS Development forum on this site for years. The Administrators simply thought it would be a good idea to expand that to include MorphOS as well as Linux PPC Development. After all, both affect the Amiga community and if you want to be seen as unbiased (which Amiga.org does), one should support everything.
I even heard a rumor that they might also be adding an AROS Development forum as well, if someone wants to make the case for its existence.