Not only the DE-CIX route servers are filtering against IRR databases. Your transit carriers are filtering against routing databases like RIPE, APNIC, ARIN or Merit RADb too. Having wrong or missing entries means:
potential traffic path problems,
unexpected paths are used,
no usage of should-be-used IP infrastructure is given for these prefixes
and even a loss of revenue for you is likely to happen when customers traffic is using other alternative paths instead of yours.