Underhill also said to expect multiple notable players to be shipped out this previous offseason to preserve DA's culture. Which didn't happen. All the talk of Lattimore wanting out and he stayed, didn't demand a trade, and performed at a level that easily makes him the best player on the defense and one of the top Corners in the league. Kamara could have just let the Saints cut him and gone to finish his career with Sean Payton in the Orange and Blue version of the Saints, instead he signed an extension to stay in New Orleans.
There was a huge amount of concern that Carmichael had saved his job with how the Saints offense finished last season. Then when he wasn't fired on Black Monday, serious panic set in. He still got fired.
I totally get the sentiment that we're stuck with DA because of the support/silence from the front office he's gotten, but history says that Loomis and co. aren't going to make a move with a coach until the offseason and they won't do it on Black Monday either.