I believe if not all of the cryptos can be stored and sold through use the germany bank but it must be there will be some qualifications that must be passed by the altcoins to able listed on the list. It will never be the germany banks will be added any crypto without seeing the qualifications of the crypto itself.
This just like when you are seeing a cryptucouncilrating created by US exchange sites members like coinbase, bittrex and etc. Major crypto might have added by im not sure if that will be a lot of kind altcoins will be added.
In my opinion, there will be regulations as they apply in America. Only securities can be listed and of course not all altcoin will be able to register. I think with the regulation of the German Government which is increasingly friendly to cryptocurrency, it will give more confidence to investors.