First: it's very difficult to grok copyright issues from a one-sided, non-legal presentation. Settled case law means going to trial and often going through multiple appeals.
Second: as it stands, this looks more to be a contractual than copyright matter (Elsevier is contractually banning use of automated text processing by subscribers), though it might possibly attempt to put teeth into this by asserting copyright. The remedy sought by Elsevier would be not to allege infringement, but to cancel future subscriptions. It might be nice for, say, a large collection of institutions to call Elsevier's bluff.
Third: Copyright law as it exists (and particularly in the US where I understand it reasonably well) is very mechanical: it governs the making of copies of an expressive work. Copyright does NOT govern facts, it does not apply to works which are not expressive, it does not apply to works which are functional in nature.
The real test here would be to put this (and possibly other) contract claims to test in a court. Unfortunately, contracts are governed (in the US) under state, not federal law, and while there's some uniformity of language, it would probably take several such cases (and appeals to at least the Federal Circuit) to establish reasonable case law.
Otherwise, what's significant about this to me is that, once again, it's a case far less about the availability and copying of information (journal articles are routinely copied), than it is about power and control within an information market. This is an area in which conventional economics is far too often lacking (though it's also an area in which much interesting work is starting to happen).