Even if wiki isnt always reliable; The Slovenes of these areas lacked any form of collective minority or linguistic rights until the year 2000, when the Law for the Defense of the Slovene-Speaking Minority was passed by the Italian Parliament.
It may be that I am making confusion with the Slovenes in Venezia Giulia, whose rights had been long recognised. However, it strikes me as odd, since in Italy this sort of things have long been a regional competence, and the region is the same (indeed, the presence of a Slovene minority is part of why that particular region, among others, has a constitutional special status of autonomy). It IS true, however, that around 2000 minority languages got a wider slate of rights all over Italy, including areas, and languages, that previously were not recognised, or only marginally so.