I know everyone is an expert in here and has multiple exchanges of their own and are happy to state how THEY or Cryptopia SHOULD have done things but thats not the case.
Some of use here are business owners or have been involved in the management of a business and we know very well how customer relations should be handled. What Cryptopia is doing - keeping silent - is at least suspicious and very worrying from a customer relations perspective. Effectively severing relations with your customers and perhaps sending some anonymous persons to annoy the user base shows that you don't want customers any more.
Also Cryptopia doesnt "instantly" delist coins, their knowledge base site specifically states when a coin was announced to be delisted and when it will be delisted (usually a month later).
Actually they did just that - they suspended trading at the moment of the announcement, that's an effective delisting.
Why would they continue to allow trading of a coin that doesn't meet their listing standards that is being delisted? You're saying they should allow people sell the coin that doesn't meet their listing standards on the exchange, rather than withdraw it elsewhere like they do.