The model Elsevier operates on is under attack from a number of sides. In addition to UC, there is Plan S:
> The plan requires scientists and researchers who benefit from state-funded research organisations and institutions to publish their work in open repositories or in journals that are available to all by 2021.[4] The "S" stands for "shock".
https://en.wikipedia.org/wiki/Plan_S
The plan is backed by a wide range of European groups.
Elsevier may have a right to license its content as it sees fit, but the market as turned against its business model. The company now must decide whether to go down fighting or acknowledge the inevitable.
An of course, there's the ever present Sci-Hub, which presents a comprehensive selection of research papers far better than Elsevier ever did - and at no cost to the reader.