Neo is often called a better version of Ethereum as it offers fasters transfers and more transactions per minute. However, more exchanges support ERC20 tokens than Neo’s NEP-5 and perhaps that is why NKN token is performing a token swap from NEP-5 to ERC20.
To get your NKN’s NEP-5 tokens swapped, you will need to use their online swap tool or send your coins to gate.io, which will convert them for you. If you send them to gate.io, you will be able to withdraw the new tokens to your ERC20 wallet after January 7th 2019. Deadline for the token swap is March 31st 2019.
Swap ratio is 1:1 so you are not getting any additional tokens.
Swap one NEP-5 based NKN tokens (Asset address: c36aee199dbba6c3f439983657558cfb67629599) to one ERC-20 based tokens (contract address: 0x5Cf04716BA20127F1E2297AdDCf4B5035000c9eb). The swap ratio is 1:1.
NKN mainnet will be launching on June 2019 which is when the platform will have its own blockchain.
Another thing to keep in mind is that this token swap is voluntary. You can keep you NEP-5 based NKN token and do the swap to final NKN token upon mainnet launch.
Also, there is no change to total number of NKN token issued or token economics.