Purpose of this trade:
-The Jets get the better young defenseman.
-The Senators get the better fit given they already have Chychrun, Chabot, and Sanderson as better PP 1/2 options. Stanley can play the #6 role as a physical presence, and kill penalties.
-The Senators clear approx. 1M in cap.
-If the Senators waive Joseph and get back 1.15M, this trade along with assigning Joseph to the AHL clears up enough cap space to sign Pinto to a 2 year contract at 2.XXM and ice a 21 player roster.

Waiving Joseph would be a mistake

Nobody is going to claim Joseph. He has too much term and money relative to how he is playing.

In a scenario where Joseph is waived, Joseph is almost certainly better than whoever is the Senators #12 forward. The reason Joseph is waived is that you have to look at the totality of the situation. Which is that waiving him and giving his roster spot to a league minimum player like Sokolov nets the Senators 350k of cap, which in conjunction with trading Brannstrom would give the Senators enough to sign Pinto and run with a 21 player roster.

Winnipeg won't be trading Stanley for Branny the bust unless Ottawa adds a nice sweetener.

I think the Jets just keep the better player.

Doesn't Joseph's salary still count against the cap even if he's waived and sent down because it's over 1 million?

The Sens would still get $1.125M in cap relief if they sent Joseph down, anything he earns above that would still count against Ottawa's cap.

There'd be no danger of losing Joseph on waivers either. In fact if they thought someone might actually claim him they'd send him down in an instant.