I'm not quite clear what Alex is observing about rebranding of the New documents Jean is talking about. Let's break it down into parts.
If someone who did not hold the copyright made a derivative work of those documents to rebrand them for Apache OpenOffice, change screen shots, etc., they would need to honor the original license. (If it is dual licensed the creator of the derivative has a choice which license(s) to produce the derivative under.)
If someone who held the copyright on the New documents were to make the derivative, they could certainly offer a different (dual) license. By either route, even if one of the available licenses were an Apache ALv2 license, it still would not constitute a contribution to the Apache OpenOffice project. Contribution is a separate act.
Now, to have it also be contributed to an Apache project, there would have to be a contribution agreement (iCLA). Whether that is done or not is a separate decision.
An Apache project, or any other project for which the ALv2 license is compatible could also rely on the new document as a 3rd party work. In the case of an Apache project, this would not happen if the licensor objected.
A final example: If I wrote a new document that applied to LO and licensed it in a way that TDF accepts, I could also rebrand and modify it myself and offer a different license on that version. I am in a position to go farther and contribute the rebranded one to the Apache OpenOffice project too. That involves more steps, even though I have already registered an iCLA with ASF.
[I'm not going to get into how ODF Authors and others might hold joint copyright and how that complicates new licensing and especially contribution to ASF.]