Yes, but the usual significant expected risk is in the market value of the speculative commodity, not whether or not the broker ever bothers to execute your order.

Its one thing to speculate on price of BTC, its another to worry about whether your exchange will hold up.

The problem isn't speculation, but rather that he paid money and was informed he would receive the coins on a certain date, but did not receive them then.

The "price lock in" is perfectly valid so long as they inform the buyer the length of the processing period. If they give false information about that, though, it's the vendor's fault, not the buyer's.