I hear what you are saying and understand it to a point. Aiki as a simple term can be applied to many different things in an energy blending, harmonious, joining, or avoiding type of context - however, when speaking of Ueshiba's aiki, more and more independent information has been surfacing in the last few years that is painting a different picture of what many in modern Aikido have been told was Ueshiba's aiki. So for any party to state this is the true Ueshiba aiki without providing detailed documentation supporting their view point does not carry much weight - IMO, I think the IP/IS crowd has done a fair job of providing detail to support their position, but the only thing I keep hearing from the other side is that they are all wrong because that is not what their teacher taught them. In addition, the IP/IS crowd is starting to show people developing unusual power in their Aikido as well as other arts the group is involved in; where are the modern Aikido teachers with the same level of unusual power approaching Ueshiba's?
If someone is not interested in the type of stuff we do and wants to keep their Aikido the way it is, that is fine - just don't say we are wrong and you are right without experiencing both approaches - everyone in the IP/IS group has extensive experiences from being on the other side at one time - how many from the non IP/IS group can make the same claim?
I agree talking about "true Ueshiba Aikido" is...problematic. And I think we'd all have an easier time if we avoided that issue more. The OP couched the video in terms of his understanding of aiki, which may or may not be right (in terms of "pure" Ueshiba aiki), but I thought the point was less about what aiki is than what he saw as good movement when being pursued by multiple people; I can see how he might have just been referencing the fact that his idea of aiki is different from what is very often mentioned on AikiWeb these days (a version I personally put a lot of stock in...as far as I can understand it, at any rate). I see that as an honest way of framing the basic premise made here that this video is a good example of aiki (aikido-like behavior).
That all said:
A similarity I see between that idea (exemplified by high level athleticism) and the old Asahi film is that O Sensei never stays in the middle of all those people; at some point he moves away from them, finding a safer space to reorganize. If aikido (not necessarily aiki itself) was "always" about engagement I would think he would stay in the thick of it rather than moving away from it. As I currently interpret things, aiki is about how one engages themselves (i.e. a meta-operating system) which then affects how interactions will manifest. Using the intent of the attacker against him is good aikido, even if perhaps it's not sufficient to be called pure internal aiki. So rather than getting caught up in the language, which I would agree is an important topic on its own, I'd just rather see more engaging of the valid points being made that are salient to the common training experience.