ISTM this is just the end-to-end principle taken one step farther. Instead of intelligence residing in the endpoint node, now it resides in an app running on the endpoint node.
That isn't to say that the "aol2" phenomenon doesn't pose the risks to users described in TFA. I only observe that the same factors that encourage end-to-end (flexibility, reliability, loose coupling, etc.) probably encourage "aol2" as well.
No, it's a moving of the "ends" and insertion of a middleman. If I write some text and publish it to people, rather than sending it from my computer to theirs I send it to an intermediary, who reformats it and presents it to other users of that intermediary.
TFA is really talking about two things. I responded to the "layered on top of HTTP" point, while you seem to be talking about the "silos of end user data" point. Perhaps the first point contributes to the second, but I'm not convinced. Users could choose http apps that don't silo.
It strongly tends to, because having your own computer (especially a phone) set up to answer inbound HTTP is both administratively difficult (fiddling with NAT and dyndns, etc) and a security risk.
This is Schneier's argument about "security feudalism". And to some extent touched on by the article - people build on top of well-understood transport layers in order to reduce risks, and novel protocols are firewalled in case of novel risks.
That isn't to say that the "aol2" phenomenon doesn't pose the risks to users described in TFA. I only observe that the same factors that encourage end-to-end (flexibility, reliability, loose coupling, etc.) probably encourage "aol2" as well.