IBM's primary sales channel is enterprise, where branding makes all the difference. Most of the time, the person authorizing the project has no idea on the technical details (and may or may not have solicited internal technical commentary).

These deals are honestly mostly about trust. Do they trust IBM / {vendor} has the expertise to deliver the project? Given that it's mostly bespoke integration, branding the entire IBM AI/ML area as "Watson" isn't too disingenuous.