Whether the McGill rule falls outside the FAA's saving clause because it is not a ground that 'exist[s] at law or in equity' for the 'revocation' of any contract?

QUESTIONS PRESENTED The Federal Arbitration Act makes written arbitration agreements “valid, irrevocable, and enforceable,” although its “saving clause” permits the application of defenses that “exist at law or in equity for the revocation of any contract.” 9 U.S.C. § 2. But evena defense that falls within the saving clause is preempted by the Act if it interferes with fundamental attributes of arbitration, such as bilateralism. See Epic Sys. Corp. v. Lewis, 138 8. Ct. 1612, 1623 (2018). In 2017, the California Supreme Court announced for the first time that provisions in predispute arbitration agreements waiving the parties’ right to seek “public injunctive relief” in any forum are contrary to California public policy and unenforceable. See McGill v. Citibank, N.A., 393 P.3d 85 (Cal. 2017). This so-called “McGill rule” effectively precludes bilateral arbitration of consumer disputes in California. The questions presented are: 1. Whether the McGill rule falls outside the FAA’s saving clause because it is not a ground that “exist|[s] at law or in equity” for the “revocation” of any contract? 2. Whether, even if the McGill rule falls within the FAA’s saving clause, it is otherwise preempted by the FAA because it interferes with fundamental attributes of arbitration by negating the parties’ agreement to resolve their dispute bilaterally?