How does supply and demand affect roll yield? because, storage, contract

DoubleDip

If supply of commodities is abundant, is it contango? I read somewhere that it is because a producer, commodities producer, needs to keep his inventory and he adds storage cost to futures contract. That's why longer maturity futures contract is higher than short maturities.

But I also read that if commodities users dominate the market, it will be contango because they want to make sure that they have enough commodities and are willing to accept higher price for commodities.

Are these statements correct? And are they related?