I don't think this is a problem. The CLA is there to avoid future legal disputes. It prevents contributors from initiating IP lawsuits later on, which could cause significantly more trouble for the project.
Hypothetically, isn't one of the "legal disputes" that's avoided is if the projects relicenses to a closed-source model without compensating contributors, the contributors can't sue because the copyright of the contributions no longer belongs to be them?
Hypothetically, isn't one of the "legal disputes" that's avoided is if the projects relicenses to a closed-source model without compensating contributors, the contributors can't sue because the copyright of the contributions no longer belongs to be them?