Right now they are using the Binance blockchain, so their tokens are BEP2 atm. Will this change when they release their mainnet next month?
I hope it doesn't change much. They have already started with binance blockchain. So I guess the binance part of the project won't be affected.
COS being a binance blockchain based token means they can are listed on binance DEX which gives COS tokens more token liquidity. I dont think the mainnet is about the tokens. The cryptonomics could be left on binance chain, while the ecosystem would be moved to the mainnet after test.
I don't really understand your point as it relates to the cryptonomics. But I agree with the fact that tokens should still be allowed to trade on binance DEX as its a good platform which would contribute to the project development in a substantial capacity. You would agree with me that almost every project would love to get listed on binance DEX.