Do good business reports use inverted funnel format?

No, a business report is a summary of activity or numbers (statistics) from the level of management at which the activity takes place to a management level above it. The format of a business report is determined by the information that the recipient level needs to monitor the activity, evaluate, and make decisions for future activity.

A business report compiled by a personnel manager, a purchasing department, a product development team, or inventory management would have vastly different information to report and the format of the reports would differ also.