What Apple has said about it
Adam Dema, a spokesperson from Apple told Forbes the company was currently investigating complaints about MetaTrader, and will take action to protect App Store users.
When will MT4 and MT5 return to iOS?
It's still unclear whether MT4 and MT5 will return to the iOS App Store anytime soon or if Google will follow and remove MT4 and MT5 from it's Play Store as well.