This isn't about betting per se, it's about expected and/or anticipated performance versus actual. This is more that the entire IND team (not just a receiver, a missing receiver, a QB or a DL or such), all 50+ players at about ~107% (just a guess, +3 days rest) effective compared to an average 7 day rest schedule, vs NE which will be about at ~98% (due to b2b travel). [These % numbers are just estimates for an example] Add another +10% for the home advantage. NE is hurt, lost LT, lost CB, a ginger MLB, so they get addl -5%. All positions that no one follows, not really factored into the line. IND QB situation, we all know about that. Motivation for both teams are equal if you think about it. IND also having 3 days extra to game-plan.
Put any equivalent strength rested Team A, and Team B in this situation, ignore any hype, which one has the advantage? But wait, now I say Team B, really, really.... really, I mean really wants to win this game, does that affect the underlying fundamentals?
So I think we see a stronger effort than expected by IND early. Once any initial "jump" dies out, you'll see both teams play closer to normal home vs. away NE vs IND levels. We will see.