That's a big if. In reality, they won't be adequately informed - they'll be at best adequately disinformed by the marketing departments of the power companies and third parties popping up around variable-pricing schemes. And to the extent exposing the customers to price variability is beneficial for the suppliers, the market has a nice way of removing the previously available options from the choice pool.
There's a spectrum between "let the people decide for themselves" and "the people will predictably decide to do something stupid and then they'll beg to be bailed out, so perhaps let's not offer that option", and I feel this may fall closer to that second end.
Heads you win; tails someone else loses; how much would you like to wager?
So a bunch of people do something obviously stupid - like getting scammed by a tech support call, or get infinite debt on a payday loan, or put a hand in a moving machinery and lose it. Now they're there, scammed, without money, and/or a hand. What are you going to do? Deny them healthcare and basic support? No, we help them anyway, and instead chase scammers, put limits on payday loans, and enforce safety requirements on equipment - we take away the choice of being stupid, because that's more reasonable than being indifferent to the suffering of victims of their own stupidity, for the sake of enforcing a corrective feedback loop.
If a traditional electricity supplier tried to buy all their electricity daily at the spot price and not hedge against any risk, they would quickly go bust. So why is it sensible for consumers to be allowed to do that? Some businesses may buy their energy at wholesale prices through their supplier, say an aluminium smelting factory. But those businesses will have full time traders who are also buying insurance/derivatives to protect against volatility in the market. Consumers should insure themselves against that risk too, by using a more traditional energy supply contract.