Colts should be treated just like the Ravens, regardless of previous wins.
It's also important to add that the Ravens were treated like they were precisely because of previous wins in their battles against the Patriots in the past. With many claiming them to be the one team they didn't want to see in playoffs.
To put it another way, just like for the Broncos, the Colts were a playoff matchup (among other teams too) they didn't want to see. In large part because the Colts had beaten them last season, and played them tough to start the season while Manning was still playing relatively well. Now, with Manning's play fallen off of a cliff, it wasn't that hard to see the upset coming.
Just like it wasn't that hard to see that the Ravens would play the Patriots tough like they always do, despite New England's perceived advantages.
It's a lot easier to use
recent past matchups as a reference point in terms of game expectations based upon matchups (favorable or otherwise). There's no past data to suggest that the Colts unfavorable matchups have suddenly become favorable. There are areas of their attack that the Patriots have successfully exploited that they haven't greatly improved upon since then.
So if people are more confident in the Patriots' ability to vanquished the Colts than they were against Baltimore, it would be precisely because they've seen the Ravens give Patriots all they could handle before, whilst Indianapolis has had their doors blown off in three matchups. Dominating an opponent
multiple times consecutively in the past makes it far likely that it can be done again. In most cases, what that shows is that the Patriots have their number.