If you lose :latest, and the build breaks, you need to spend unexpected time fixing the build, for whatever reason that :latest broke it, in order to continue with the business objective that you were actually tasked to do. Essentially, you have InfoSec muscling in and demanding, by the most coercive way possible, that Thou Shalt Not Do Your Job Without Bowing Before Me. Who cares what the business wanted? Who cares about predictable schedules? Who cares about delivering for a customer by a point in time which was promised to the customer?
This isn't the way to promote a healthy culture in the company. Nobody should get immediate and total veto rights. In the real world, healthy organizations balance between different stakeholders, and once a path is set, everybody shuts up and executes. The right place to make a stand for your interests is in the stakeholder meeting, not the deployment pipeline.