Institutional Repositories (IRs) are for institutional research output (mostly their authors’ final drafts of their published, peer-reviewed journal articles). IRs are not for institutional buy-in of the output of other institutions. (That would be an institutional library.) The way Open Access (OA) works is that an institution makes its own research output free for all online, to maximize its visibility, usage and impact. By symmetry, the institution’s users also gets access to the output of all other institutions’ IRs, for free. No subscriptions, no fees, no consortia, no need for an institutional affiliation for anyone but the author of the work in the IR.
That?s OA. Almost-OA is when some of the IR material is still under a publisher embargo, so it is deposited as Closed Access instead of Open Access and can be accessed using the IR?s almost-immediate ?email eprint request? Button during the embargo. Almost-OA is not OA, but together with universal Immediate Deposit mandates, it will soon usher in universal OA.
In contrast, Joseph Esposito?s ?Almost OA? is just institutional consortial licensing. It has no more to do with OA than being Almost Pregnant has to do with parity.