Not really.
TDK had good legs, not 3.5x but 3.36x. I think you mixed it up with SM1 which had one of the best (third) legs for a comic adaptation so far (in the last 20+ years). Based on the drops so far, Avengers is looking at a run closer to Thor's rather than TDK's, for obvious reasons. That still gives it 570M+ which is not a small number by any means. That would mean that Avengers will have the weakest legs in the top 5 and top 10. What he probably meant was that people are now reeling in their estimates, when original some had thought this would outgross Avatar (lol), Titanic (w re-release), the chance of that is now slim to none.
As for THG, it still is an impressive run. 2.65x multiplier is nothing to sneeze at when you consider the movies in its genre hover around the 2x mark. Not only the legs but the opening weekend also had amazing numbers, especially for the first book of the series.