Since this week Skype for Business PSTN Calling is general available in The Netherlands and Ireland. As described in March PSTN Calling was in Preview in The Netherlands and Ireland, but it is now available to all Office 365 customers in those countries! On this site you can see Ireland and The Netherlands are not marked anymore with “Only in Preview”, like Belgium and Germany still are.
Now I`m able to add phone numbers in the Skype Admin center, so I can assign them to my users. Unlike in the other countries, new numbers for The Netherlands and Ireland most go through the service desk first.