Nothing in this ruling (based on my relatively quick read) stops companies from implementing countermeasures. It's not illegal to make it hard to do something legal; for example, DVDs are protected by CSS, which although it's laughably easy to break, does stop you from exercising some of your fair use rights (which this ruling also recognizes).
Whether companies can implement things like eFuse or whatever is generally the realm of antitrust law, which is another ball of wax entirely.
This last sentence, from the article, indicates that this ruling is actually a step backward:
"On EFF's request, the Librarian of Congress renewed a 2006 rule exempting cell phone unlocking so handsets can be used with other telecommunications carriers. Cell phone unlockers have been successfully sued under the DMCA, even though there is no copyright infringement involved in the unlocking. Digital locks on cell phones make it harder to resell, reuse, or recycle the handset, prompting EFF to ask for renewal of this rule on behalf of our clients, The Wireless Alliance, ReCellular and Flipswap. However, the 2009 rule has been modified so that it only applies to used mobile phones, not new ones."