They shouldn't.
If the seller is scratching off the Rimowa case ID Nr. digitally in the Ebay photo, that is a minor issue. Verify the Nr. with the seller.
Any seller physically removing a Rimowa case ID Nr from the case, is another matter. In this case, that is reason enough to assume some sort of fraud is occurring.
Rimowa case products are guarantied for 5 years. If a new case has been cracked while travelling, some here have reported that the damaged case was replaced with a new model, with the original case having the ID nr. cut out and removed as a replacement condition.
Thus Buyer Nr. 1 buys a case and has it damaged. Rimowa replaces this damaged case upon receipt of the original case ID nr. cut out and sent in. They then send out a new replacement case as compensation to Buyer Nr. 1. It should end the process there.
If that same Buyer, or someone else is then trying to " pawn off " the cut and damaged case for an extra fee, they are milking the cow a bit too much, making money off a case that they have already received compensation ( the new replacement ) for. That too would be reported as a clear case of fraud: It might even have been stolen.
Don't buy it, or pay for it, as there is something wrong with it. If it is delivered as such, contact the Ebay Resolution Department immediately, and return it for a full refund as a " Not as described - Damaged case " in your Resolution Claim.