This is actually absolutely no fact.IMO there is no validity to be proven, it is a fact that TRH'nesses have not given an interview to the Danish press, but have obliged the foreign press, and this is the bone of contention that motivated the article, along with the possible reasons for this deficit.
They have given several interviews to the Danish press and TV before their wedding, at the time of the wedding and after their wedding, for example when they visited Greenland, the Faroese, Bornholm or when they left the hospital with their newborn children. Mary and Frederik usually answer questions of the press when they are out on duty or for example on Christian's first day in kindergarten.
They gave an interview to Australian TV in connection with their visit there and, as it was stated back then, because they had not given any interviews to Australian media around the time of their engagement/wedding (whereas they gave a lot of interviews to Danish TV).
Besides, Mary posed once for an Australian fashion mag and once for a Danish fashion mag.
This was in late 2004, early 2005 and since then no TV station or fashion mag from any country got a personal interview or photo-shoot AFAIK.
They visited Germany twice and - unlike for example the Norwegian couple - they refused to give an interview beforehand, which actually upset the German media a bit IIRC.
So, one really can't speak of obliging the foreign press and ignoring the Danish press.
The editor of Se&Hor is complaining since 3 years now that Mary doesn't give an interview to the trash mag he is editing (my description) while she gave one to a serious Danish paper like "Politiken", actually he accused Mary of being a snob. And now suddenly they come up with the "possible reason" that her Danish isn't good enough for an interview? That really makes me laugh.
And why on earth should they give a big TV interview right now, only ~3-4 years after that overload of interviews in 2003/2004? There is no wedding, no visit to another country, no 40th birthday...
I remember Mary was critizised a lot on this messageboard for being too "media-crazy" and now she is critizised for not oliging the Danish media? Very strange.
I personally think the moment the CP couple starts giving interviews for no reason at all and to gossip mags like Se&Hor the DRF would be in real trouble (and loose my respect).