This grant is not a payment to Binance for adding support. Instead, Binance is asking for a temporary listing deposit that will be held in two tranches: $100,000 USDC for 12 months, and the remaining $100,000 USDC for 24 months. This deposit will be used by Binance to cover any losses to user funds or the exchange in the event of an issue with the transferring of funds, the bridging of DYDX ethereum to DYDX v4, and any possible issues with the new protocol. Following discussions with Binance, this is their preferred solution when supporting newer protocols.
As such, the DEP can expect to receive the full grant back from Binance in 24 months, assuming no significant issues with the dYdX Chain.