The casino does not see it that way, look to me how I understand the way they do their calculation is, they are using the current data as in price to factor out their VIP level up. It's just like saying you bought a lamborghini for $500m and after 10 years you still expect the newer version of it to worth same amount. No this will not happen that way, if you spent your bitcoin at 20k you don't go back to have them at same 20k rather the price has inflated, therefore casino would never do that because they will run into a series of lost if that is implement because there were people who lost 100 BTC to some gambling site if that is awaken automatically they leveled up to VIP causing a huge damage to the site. I hope you understand what I meant positively.
So, are you disagreeing with what OP shared?
We can simplify the explanation, all casinos typically use a USD value to rank their VIP clients. For instance, let me share an example from one of the most popular casinos, which I’m sure many of us here are familiar with and actively use.
https://help.stake.com/en/articles/9968893-what-are-the-stake-vip-levels-benefitsVIP Levels & Benefits (1 point = $1)
These are the points you need to level up as a VIP player:
Bronze: 10,000 points
Silver: 50,000 points
Gold: 100,000 points
Platinum I: 250,000 points
Platinum II: 500,000 points
Platinum III: 1,000,000 points
Platinum IV: 2,500,000 points
Platinum V: 5,000,000 points
Platinum VI: 10,000,000 points
Diamond I: 25,000,000 points
Diamond II: 50,000,000 points
Diamond III: 100,000,000 points
Diamond IV: 250,000,000 points
Diamond V: 500,000,000 points
Obsidian: 1,000,000,000 points