I believe the conversation you are thinking of takes place when Haley and the MC start out to explore the old neighborhood. She says, "It's different though, isn't it.", he responds, "What?", "Everything.", "No. You're different. You're looking at it through different eyes." That doesn't give me any indication that they have been home recently.
If you review the conversations when they went to the lake, it seems like they hadn't been there in a while.
Then there is the meeting with Nick, where it sure looks like Nick might have put on a few pounds.
Not only that, but on the drive back home, Haley says, "It was nice to see them, wasn't it?", to which the MC responds, "Yeah. It's been a while.".
To me, everything in the game points to them being away since having gone off to college... at least. There are just too many references to the 'old days' when they were in high school for me to think differently.