Just a point to add to this discussion and to point out that 42psi has made some very good posts.
A/C de-icing fluid also l am told is in short supply and not only at MAN.
Maybe the handling agents who have to accept the diversion, might be saying yes we will handle you but you will not get de-iced.
The handling agents keeping what stock they have to cover their scheduled commitments.
I as an airline l would be well p***ed off if you turned round and told me that l can't de-ice your a/c because l had been de-icing every Tom Dick and Harry the last few days.