The more I think about it the likely a 2nd season pass becomes, for better or worse.
Think about it. Fallout 4 released a year later than usual, leaving a 2 year gap with no output from BGS. Papa Zena couldn't have been happy, similar to GTV imo. Whether the delay was for next gen retooling or general development load increase is unknown, but its not a stretch to think that ES6 will be a 4 year gap too. Either way, last time they had NV. They need something to fill the gap. Another year of dlc will put them right on the doorstep of ES6 at E3 in '18, or will give the GOTY edition a year to itself if '19.;
So yes, I think we'll see a second season pass, and possibly a year of small free dlcs, to help bridge the gap to the next Elder Scrolls. If done right Fallout could have some impressive legs.