GNOME 3.8 to drop fallback mode

That paragraph out of context is misleading, and I do not think the wiki page set the whole context for outsiders. I think it reflects a view rather than actual blocks or rejections.

In the last 2,5 years there are just very few patches submitted to gnome-panel, and only one (yes, 1) has been rejected for the reason given in the paragraph. Which is the following one: https://bugzilla.gnome.org/show_bug.cgi?id=674580

There were others bugs reported before GNOME 3.0 that were declared obsoletes, but those can't count as contributions to provide an alternative UI to GNOME 3.0.

I have been following gnome-panel bugs since I helped to ported it to GTK3. Even back then there was a lot of rant and, as we see today, some people assumed bad intentions, but the truth is that there was almost nobody really stepping up to give a hand.