I did a little research and it seems like the law is on Yuzu's side in this case. After consulting the U.S. Code of Federal Regulations, Title 37, Section 201.40, it seems like it is perfectly legal to circumvent technological measures if the purpose is to preserve video games, or make them accessible to people with physical disabilities. Citing the CFR:
(b)
Classes of copyrighted works. Pursuant to the authority set forth in
17 U.S.C. 1201(a)(1)(C) and
(D), and upon the recommendation of the Register of Copyrights, the Librarian has determined that the prohibition against circumvention of technological measures that effectively control access to copyrighted works set forth in
17 U.S.C. 1201(a)(1)(A) shall not apply to persons who engage in noninfringing uses of the following classes of copyrighted works:
17.
II. Video games in the form of computer programs embodied in physical or downloaded formats that have been lawfully acquired as complete games, that do not require access to an external computer server for gameplay, and that are no longer reasonably available in the commercial marketplace, solely for the purpose of preservation of the game in a playable form by an eligible library, archives, or museum, where such activities are carried out without any purpose of direct or indirect commercial advantage and the video game is not distributed or made available outside of the physical premises of the eligible library, archives, or museum.
III. Computer programs used to operate video game consoles solely to the extent necessary for an eligible library, archives, or museum to engage in the preservation activities described in
paragraph (b)(17)(i)(B) or
(b)(17)(ii) of this section.
18.
I. Computer programs, except video games, that have been lawfully acquired and that are no longer reasonably available in the commercial marketplace, solely for the purpose of lawful preservation of a computer program, or of digital materials dependent upon a computer program as a condition of access, by an eligible library, archives, or museum, where such activities are carried out without any purpose of direct or indirect commercial advantage. Any electronic distribution, display, or performance made outside of the physical premises of an eligible library, archives, or museum of works preserved under this paragraph may be made to only one user at a time, for a limited time, and only where the library, archives, or museum has no notice that the copy would be used for any purpose other than private study, scholarship, or research.
21.
Video games in the form of computer programs, embodied in lawfully acquired physical or downloaded formats, and operated on a general-purpose computer, where circumvention is undertaken solely for the purpose of allowing an individual with a physical disability to use software or hardware input methods other than a standard keyboard or mouse.