There will be no any incentive for the one who will pay for those ads. However I think we may see some tv ads in near future from bitcoin related local services in few countries to promote their services.
Absolutely, since bitcoin is open source, no one in particular is going to make any profit promoting bitcoin through TV ads solely as a currency. The legality of bitcoins is an issue, in most countries bitcoins has not been declared illegal, but still they have not accepted it as a legal currency. Might be due to this even the most die hard bitcoin enthusiast with some spare bitcoins would think twice before going forward with bitcoin as a currency TV commercial idea.
But, promoting bitcoin as means of a payment system through TV ads for services is safe. For example this Bitpay ad, https://youtu.be/Rm7wgmwKiAk
Bitcoin even made a special appearance in Deadpool. So bitcoin is catching up.