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.
No one in the IP/IS group ever said that moving out of the way was not a valid martial movement; it can be done with or without aiki, and in of itself, it really is not aiki; just part of an external jujutsu movement. As said, If that is how one looks at it and likes to keep their Aikido in that frame of perspective, that is fine. What we are saying is that there is much more out there, and for those looking for more, here is something to look into - simple as that.