A number of members may attend the committee meetings at the same time. However, the 40 members from one party sitting at the table wouldn’t all be authorized to speak. We know that there must be five Liberals—including the chair—four Conservatives and one Bloc member. This wouldn’t be a breach of parliamentary privilege.
The proposal simply states that, when a substitution takes place, the substitute member must be identified. This doesn’t prevent a member from speaking. This is about letting all committee members know who can speak, based on the rules of procedure governing the number of people eligible to attend a meeting.