I'm afraid the use of port 445 is not a new and random port choice by Microsoft, Tollef.
$ grep 445 /etc/services microsoft-ds 445/tcp # Microsoft Naked CIFS microsoft-ds 445/udp $
This port assignment has been in place with IANA for several years now, and actively used by Microsoft implementations since at least the release of Windows 2000. If anything, your Uni's policy change seems to come a bit late to the game. But I guess that also explains why they've done badly enough with it that they're dropping packets on the floor...
Needless to say, trying to stop people from implementing new network protocols and asking for new port assignments would be futile. ;)