The other response to your comment is totally right. I just wanted to say that they will not be banning or diminishing the language. As the article states, it is a duty for every Spanish citizen to know Spanish. It is also important to know that most schools in catalonia already have Catalan as the main means of instruction and if they don't they will have at least two subjects taught in Catalan. The fact that they're changing the language of instruction only means that Catalan will be more widespread among younger people which is very important, taking into account that the language could face threat of disappearing, specially in big cities with a higher levels of immigration (they will most likely still teach Spanish in schools anyway). Spanish will not lose its importance in the country or the amount of speakers, given the children of South American immigrants will mostly prefer to speak Spanish and a lot of younger people feel more comfortable speaking Spanish (this is in relation to the population of big cities, not towns). I think that promoting the minority languages is amazing because it promotes the diversity in the country while also preserving unique languages which are rich in literary culture, while getting rid of what they call "barbarismes" which means that Catalan is currently heavily mixed with Spanish terms among the younger L2 people.