The difference between AGPL and GPL is that with the AGPL, you also need to offer a source code download.
Personally, I like the new Mozilla Public License very much. It is short and readable, compatible to the GNU licenses (permits relicensing under the GPL), and you can combine MPLv2 works with differently licensed software as long as the MPLv2 code is kept in a separate file.
If you decide to offer moxl under the MPLv2, you don't need to remove the AGPL. You can simply dual-license it, and users can choose which license fits best for their purpose.
It would really be a problem for Friendica to use Moxl if it is only available under the AGPL, and not only for Friendica, but for any project that is not also licensed under the AGPL.
You can also have a look at the discussion at https://github.com/jappix/jappix/issues/76 about dual-licensing Jappix Mini under AGPL+MPLv2.