I don't think the latter part of that is right, but I agree with you that too many Spurs fans go around looking for slights where they just aren't apparent. The Spurs aren't media darlings, but there's nothing incorrect about saying that Lebron led the Cavs to the NBA Finals -- just as there was nothing incorrect about saying that Jason Kidd led the Nets to the 2003 NBA Finals or that Allan Houston and Latrell Sprewell led the Knicks to the 1999 NBA Finals. There's no slight in recognizing that Lebron was fantastic for the Cavs last year.
It would be different if the news readers were saying that the Cavs were the defending champions or if the story dealt with a Cavs/Spurs matchup and made no reference to what happened in the Finals, but that didn't happen. The Spurs will be called champs for the duration of this season; they don't have to be mentioned in every story about every team in the NBA during the season as well.