Are save files prior to the new update automatically updated?

[iabez]

I haven't the played the game in months but I have a safe file prior to the new update and was wondering if it is in any way affected by the update? Are the new content present in the old save or do I have to start a new save?

[ULTRA]

yes, they are updated, and the only reason to start a new save is because a new farm type was added and you can't switch farm types mid-game

[BirbNotBird]

Short answer, no, but still recommend you start fresh in 1.6.

Long answer, the patches will try to be "friendly" with old saves as much as possible. You are less likely encountering bugs, though if you are then they are pretty minors.

1.6 adds lot of content for early and mid game also (including new dialogues for event that is exclusive to Year 1). So yeah, start fresh and over, maybe with your new curated modlist.