I'd say it's FUD from 8 months ago. In that blog post they say that NoScript and Tree Style Tabs will no longer be possible with the new API. Meanwhile the author of NoScript says the new API works for him and Mozilla is making sure the new API provides the features that add-ons like Tree Style Tabs need. No need for fear, uncertainty, or doubt.

probably just unintentional fud

what is needed for a DTA-like, is some way to make arbitrary connections with arbitrary headers (which I would be surprised if it isn't provided), some way to write to a file with some reasonable control over how that file is written (writing and seeking, not the most needed thing, but would obviously be preferred), and some way to display UI (a html panel)

This might be harder or easier to implement than DTA is, but there probably won't be a direct port of DTA ever due to how tightly coupled it is with firefox