TBH, I think there is more to listing than paying a fee. If I think about it, suppose there is a non gambling token out there with the same performance, popularity and from a pretty successful business, I'd say it would have been listed in a tier 1 CEX by now. I would say it's likely that there could be some friction with tier 1 CEX and gamba platforms in general.
I have seen similar discussions before. If you noticed, the CEX does not like casinos. If users make transactions with casinos, some freeze their accounts. For example, coinbase freezes a user account if they find that you are making a deposit to a casino. I don't know about other CEX, but I do believe the exchanges do not like casinos.
As for listing casino tokens, I feel most tier 1 exchanges won't even list casino tokens. Do we have any examples of listing casino tokens? I don't remember seeing any exchanges listed casino tokens before. Not sure if we will see it in the future.
I don't know if there's something issue with regulation happening on why we see most of casino tokens struggle to be added on big exchange.
I also tried to view some tokens which is under gambling category
https://coinmarketcap.com/view/gambling/ have big volumes and I see Arcadeum which got $30m volume which also been listed on Bitget,gate.io.HTX and Lbank which is somehow a decent exchange.
So maybe by this that means other top casino tokens have chance to get listed and its just they need to push to make this happen.