I doubt the CC will be that bothered. There is nothing in the CC rules and regulations that prevent a charity in the UK send funds to other charities abroad. They have been doing it for years already with UK donations propping up NY and other branches.
I think this move, if true, will be down to a combination of factors. Key will be the need for Germany to have enough money to support the centralisation of the printing. Also they could be looking to hide funds and reduce the financial footprint of the organisation in the UK. They may also be pre-empting any possible exit from the EU and how that may affect things. Last, but not least, I do think they are running scared about possible CC investigations into the tax affairs of the org in the UK. This is both directly from the CC but also potentially from a royal commission type investigation into child abuse.
The funny thing is that the UK branch has considered itself really special for years and years with obnoxious, self important and puffed up leaders imagining that they were untouchable. The delight at the thought of the rug being pulled from under them is great!