I don't think that's a problem, really. You could say the same when Cadbury ended their sponsorship of Coronation St.
It's a fair point but, UTV weather/Progressive jingle/cartoon was going out 4 or 5 times a day for up to 20 years. There have been sponsors since (I think) but None would have the name impact. In the republic the weather forecast was sponsored by Telecom Eireann/Eircom for years and was called weatherline. Once the sponsorship came to an end it was called the weather, but it took years for people, papers and presenters to stop calling it weatherline.
At the end of the day companies can be slow to get involved with sponsoring media opportunities when they are associated with another company. However, I have no doubt that the opportunity and price will be right for someone and UTV weather fairly soon.