yes, there is a mistake. the deadline = o prazo.

Yes, it's wrong, it's "O prazo".

But....if the translation was: "they will lose in the long term", then "a prazo" would be right (preposition + noun).

We use "a prazo" very commonly when buying stuff. There are two buying options: "à vista" or "a prazo".

• À vista = single payment
• A prazo = the price is divided to be paid monthly (in the long term)