> We aren't allowed to sell people something that doesn't exist?
You're allowed to sell rights to things that might exist in the future.
If someone puts a ton of money into something stupid that's pretty clearly not going to pay off proportional to the expense, that's on them.
> you're promising your investors [a return]
This is somewhat different from your first paragraph. Overselling your confidence in the financial outcome of a bet is (usually obvious) fraud, but that's a different problem from selling a stake in a risky endeavor.
Not defending Telegram's stupid shitcoin, but trying to get the Government to stop this (whatever your probably loosely-held idea of "this" is) is probably not a good idea.