Without this patch, users without access to reading and editing mass mailing contact records are now unable to change a partner's name or email. They'd recieve an exception such as:
AccessError: Sorry, you are not allowed to access this document. Only users with the following access level are currently allowed to do that:
- Mass Mailing/User
(Document model: mail.mass_mailing.contact)
Restrictive ACLs shouldn't restrict normal user operation nor DB consistency, so using sudo mode now and testing behavior.