if your altcoins is mainly traded up only into this place then you wont really have any choice but as long you have sell and converted
then better to get out asap rather than to wait for an another incident.
So stands to reason those users holding coins that are not easily traded elsewhere might stay but those trading top level coins have a wide selection of exchanges to go choose from should they feel unsafe and want to move.
I still think it is much better to hold any coins in his default official wallet. Exchanges are just for trade.
I woud suggest you use Binance instead of cryptopia.because it has most of the volume and binance is mostly safest exchange.you can trust binance with your balnce.but don't hold your coin at the exchange.
what is your suggestion for coins which is not listed on Binance? what to do in that case?
Many of Altcoins was listed on Cryptopia but not on Binance. For some small communities, Binance have a too high listing fee and Cryptopia have them the opportunity to go on to the market.