I agree. The law sort of makes sense, but I am not sure how big emissions computers in general do produce - the wattage open seems to be pretty low, and most other things are well covered (prcessor, cards) under metal elements. Just anyone selling a case without CE symbol has a risk 
While I do not know the details of the law, there probably is a way around it. Sell it as metal or something that is not intended to use with computers. Though I wonder how do they test it - the case is just that - a case, how do they find out if the emissions are within normal parameters - maybe I have a device (VGA or whatever) that radiates 10 times as much as a normal device does, in which case the emissions would be higher...No, you do not. Basically the case is supposeed to be a faraday cage, and if you read up on them on the internet you find out they are either working or not working, pretty much. Either you have a perfectly grounded protection for a specific set of frequencies, then you basically dont care how much energy leaks inside unless the cage melts, or you dont, then that is it. A working faraday cage is always a 100% protection from electric energy or a non-working one.
Plus, basically, stupid games like "selling as metal" wont work if the advertising makes it clear that this is intended to be used as a case. Courts are over stupid tricks like that for a lon time. Put up a BIG warning, explaining "export only, not EMV shielded, operate in the EU at your own risk" AND explain the risks and you are ok - but then guess what, people won't buy.
Test benches are clear - this is not supposed to be used for running stuff
Testing is done with a standardized test, btw., which is quite expensive
