Cuban President Raúl Castro’s Saturday speech at the opening of the Communist Party’s Sixth Party Congress in Havana grabbed global headlines this weekend when he unexpectedly announced a proposal to impose term limits on all Cuban government officials—including himself. Under the proposed rule, future leaders would be limited to two consecutive five-year terms in office. Mr. Castro also urged a “systematic rejuvenation of the whole chain of party and administrative posts” and made clear that he would not be exempted from the rule.

Critics of the five-decade-old regime voiced immediate skepticism of Mr. Castro’s intentions. Activist Elizardo Sánchez Santa Cruz said the proposal is duplicitous because “the ruling elites are giving themselves 10 more years of totalitarian continuity.” Cuban economist Oscar Espinosa Chepe added that term limits won’t solve the real issue, which is “the monopoly on power by a group whose policies have failed for 50 years.” And Cuban-born U.S. Representative Ileana Ros-Lehtinen referred to the proposal as a “farce.”

The long overdue party congress—the first since 1997—was expected to deal with economic issues, but it is not anticipated to result in a major departure from Cuban socialism. In his speech, Mr. Castro expressed strong support for Cuba’s economic model, particularly in terms of health care and education. Yet he has also supported market-oriented reforms that include decentralization and greater private economic activity.

In his column in the official newspaper Granma, Mr. Castro's brother and predecessor Fidel Castro gave an important vote of confidence to the proposed reforms.