Quite possible. We do not have any proof of a similar postal stationery. Dutch Monthly Filatelie, in which the Dutch Federation KNBF is publishing their official announcements, was delivered today with its first issue (out of 11 yearly) for 2019. The carrier is – at least – for this year and 2020 the other Dutch postal operator SANDD.
This is not unique, as SANDD is delivering a lot of magazines as well as state mail, such as from the tax office.
What makes it unique is the new postal stationery with which the magazine has been delivered. This is a magazinekaart, not to be mixed up with briefkaart which is a postal card send by itself with a text.
The magazinekaart is for magazines. The imprinted stamp also has the value for sending of a magazine € 1,55.
Every month there will be a new stamp on the magazinekaart. The topic for 2019 is coat of arms of places where a major philatelic event (at least two days) will take place, the next month.
The magazinekaart comes with a postmark with the date of dispatch.