In terms of coach Lincoln Riley needing to guide USC to wins this upcoming season, to an extent, yes, the Trojan HC is on the hot seat. This is not, however, in the traditional sense of the term, meaning that his job is on the line, per se. For the Trojans to consider letting coach Riley go at this point in his contract, it would take a sub-.500 year and a couple of ugly losses in order for that type of conversation to even begin.
Instead, the upcoming season is more about providing assurance and preventing the program from being in a position where coach Riley is legitimately in conversations that involve his questionable job security.