The article points out that they have 79 planes from Boeing that are grounded. That it's impacting their ability to fly and finances. They may have Airbus planes but their whole fleet isn't Airbus.
> United Airlines CEO says the airline will consider alternatives to Boeing’s next airplane
This article is signaling that operators are exploring alternatives to Boeing, and revenue could shift from Boeing to Airbus in the future. That's the point of the article.