All at the same time? Woah.
It seems they over-published a bit? The market wasn't strong enough to support all these series.
If only that was all it was. It's not that the publisher dropped them because of (low) sales, which is annoying as well when it happens. It's that the re-negotiation to keep the licenses (that Kodansha gave to an entity -GP Manga- that got absorbed by another -BD Edizioni- making matters complicated I guess) failed (for whatever reasons) so they lost the licenses on all Kodansha titles (they can keep selling already printed volumes until the 30 of June for some of them, after which all leftover volumes will be destroyed).
Over publishing is the main sport for manga publishers in Italy I'd say. To give this a little context, last November 157 manga volumes were published. Number of volumes can and do vary month by month. But they wouldn't stop over publishing unless they were going under, and even then...