Completely.
“In the preseason, these components are made up entirely of data from previous seasons, such as returning starters, past performance, recruiting rankings and coaching tenure (more on the preseason component below). That information allows FPI to make predictions (and make determinations on the strength of a team’s opponents) beginning in Week 1, and then it declines in weight as the season progresses. It is important to note that prior seasons’ information never completely disappears, because it has been proved to help with prediction accuracy even at the end of a season. Vegas similarly includes priors when setting its lines.”