The Opportunity's Account will be implicitly Read for the team is something that the consultant should consider when rolling out Opportunity Teams with Private Account organization-wide defaults. An Opportunity Team is a group of users who work together on an Opportunity, such as sales reps, sales engineers, managers, etc. Each Opportunity Team member has a role and a level of access to the Opportunity and its related records, such as Products, Quotes, Activities, etc. Organization-wide defaults are the baseline level of access that users have to records they do not own or share. Private organization-wide defaults mean that only the record owner and users above them in the role hierarchy can view and edit the records. Implicit sharing is a type of sharing that grants additional access to records based on relationships between objects or users. Implicit Read means that users can view but not edit a record.
By rolling out Opportunity Teams with Private Account organization-wide defaults, the consultant should consider that the Opportunity Team members will have implicit Read access to the Opportunity's Account, meaning that they can view but not edit the Account record related to the Opportunity they are working on.