I read the story but am somewhat baffled. It seems as though eXch hosted their servers in Germany and that seems a strange thing to do. Also, it was reported over eight terabytes of server data was seized. That is a lot of data and there were reports about CM having similar amounts confiscated at the time they were seized. having said that, no reports of arrests were made.
If I understand correctly, eXch had its own nodes for each coin they had listed on their platform. Full nodes on BTC, ETH, LTC, and Dash are certainly in TB-sized.
I do not think that they would store their coins on centralized services. Therefore, there are many questions about how the coins were seized
eXch was a centralized service. Seize the server, seize the coins.
A centralized service does not have to have a wallet (and coins) on the same server as the application.