Nice insight, Nico. But no significant changes in radio and television programs, just an earlier timeslot than OTL.
Well, for starters, we can say that there is no TL where spanish TV is worse, so if anything changes it could be only for the better.
Most programs would simply change their timeslot to adapt to the new prime time, as you say. In general, spanish TV is like in other western european countries but adding an extra ration of pseudo-celebrities programs (sometimes the same programs or shows, more often american ones, but also other local productions that circulate around the continent, either dubbed or in versions adapted to local lore. In the spanish case, an example of the former would be "UPA Dance", which I have seen dubbed in french and italian TV's, and for the later "Cuéntame" that was adapted by portuguese and italian TV's as far as I know). Regarding the Radio it would very important to adapt to the new timetable, because something that makes the radio still a strong media in Spain are the political debate/humour or political debate / unvoluntary humour programs at the hours the people is going to work. Another factor for spanish radio's health are far right pensioners following crazy pundits, but that's another matter.
Probably there would some trouble regarding La Liga broadcasting. The hours when the machts are played has been a matter of divission since years ago. You have the players and clubs with their interests, the public with theirs and the bars and restaurants with theirs (since many people gather in bars to wacht the machts) So, this new change would probably open a new "debate", though in recent years there has been changes which took into consideration the international markets rather than domestic issues (i.e., playing the machts at times when it can be broadcasted also to Asia (maybe you are aware of this, no idea if La Liga is broadcasted in the Filipinas) with the hope the chinese will buy tons of Messi or Cristiano t-shirts and the japanese will come to see the Bernabéu or the Camp Nou.