Have you went through GRIMACE's deposit to list event of Bitget.?
You've got the right point ya! These kinda events help to boos both exchange & project's exposure. Imagine you're depositing your assets on an exchange, that'll be considered as liquidity of that token. Tho, those assets will remain to you,but exchange have right to use it(Open Secret). By launching those events,they try to help the project by attracting users . User's also become benefited because of the reward pool & maybe with potential price surge!