There were plenty of expiring contracts, but what is clear is, if Jerry fired Moore, he would still owe him money for his final year. The fact that the Chargers requested an interview a week prior to even announcing his hire, while Moore has connections to Herbert and LVE through some commercials in Idaho seems to support this position. This request by the Chargers also PRECEDED Dallas announcing it won't renew any expiring contracts, including Joe Philbin. Coupled with the fact, as
@NotForLong pointed out, Jerry owns the rights to box seats for the Chargers, it all points to a move on Kellen Moore' part.
It is also being reported that MM is not changing the offense, but will call plays. Since Prescott is too expensive to move this next year, maybe Jerry doesn't really have high expectations this season.