The claims made by the author seems plausible at first glance, but closer inspection reveals that it does not have adequate evidence to support the recommendation given.
Firstly, the author stated that their late-night news program has been devoting more time to national news and less time to weather and local news. However, they do not state why this is such. Has there been an internal change in the television station where national news requires more airtime than weather and local news? Additionally, what kind of viewership do they have for their late-night news program? It is possible there are more people who work 9am to 6pm jobs where they are unlikely to watch late-night news programs as they would be asleep. If this holds true, restoring the time devoted to weather and local news will not increase viewership. Thus, this claim does not strengthen the business manager's argument.
Moreover, the author does not elaborate what kind of complaints are made concerning weather and local news coverage. Are viewers actually unhappy about the airtime weather and local news are receiving? Or are they unhappy about the new weather forcaster? Understanding the complaints of viewers would help in better evaluating the underlying problem. Furthermore, complaints from viewers does not correlate to less viewership. Thus, the author is incorrect in relying on this claim to recommend restoring time devoted to weather and local news in order for more viewership.
Lastly, as the program is broadcasted in the late night, it is likely many would be asleep to watch television. As such, local businesses might deem it unprofitable to advertise on late-night television programs as these advertisements mignt not be reaching their targeted audience. Therefore, it is premature for the author to assume their loss in advertising revenue is due to viewers being unhappy about the less weather and local news coverage.
To conclude, the bases of claims made by the author have inadequate evidence to support their recommendation. Further investigation is needed for the claims stated to be able to better evaluate and to appropriately recommend future steps.