The role of a Business Analyst is to understand and document business requirements. They will also document business processes and business rules.
Wireframes are an important UX outcome, they effectively synthesise a lot.... they are a conceptual representation of user needs, the information architecture, content structure and hierarchy, the interaction design, and UI design patterns. A good UX designer should be able to explain the "why" behind every single thing in a wireframe, directly relating it to user insight that's been gained from research and testing.
So the first and most important thing; BA's should not be creating wireframes! Historically though, BA's often created wireframes because there were no UX people and, well someone had to tell the developers what to build.
BA's should be working with a UX designer to validate that the wireframes meet business requirements, that business rules are accommodated and that the solution will work with business processes in place. But to answer your question - get the BA's away from the wireframes! That is your artefact! You can demonstrate value to the organisation by being able to explain how the wireframes solve a user problem and why.
Conducting user testing with the wireframes (by creating a clickable prototype) adds enormous value because you can communicate what's working well, what's bad, and what needs to be improved - and then you iterate and do it all again.
What sets the UX discipline apart is that you're focussed on human needs. You're designing something in a human-centred way by engaging with users through research and testing. This means that you're reducing risk for the business, ensuring that what gets built is actually going to be useful and usable to the people that need to use it. That you're solving a problem worth solving!
The insights that come from user research should set UX apart because you'll gain lots of interesting things to communicate around what people really want, how they really behave and what challenges they really face. You can prove or disprove business assumptions and validate ideas.
A solution may meet business requirements, every single one of them. But meeting business requirements does not mean a solution is what users want.
Wow your organisation through your deep understanding of the user and your ability to communicate that. The best UX designers are great at storytelling. Bring all your user insight and understanding together to tell a story that gets everyone in the organisation to understand and appreciate who the user is.
Specific deliverables that you can use as part of this storytelling could include; empathy maps, personas, journey maps, storyboards, user flows and of course, the wireframes. All of that should trump a spreadsheet of business requirements.