Wasn't the damage bonus for doing a heavy attack in air removed like half a year ago? The biggest contagion nerf here is the eclipse nerf, now they just made it so you cant do the heavy attack animation in air which doesn't matter because it didn't do anything anymore for a while.
Edit:
So I did some looking and apparently it largely did still work but in my testing when it was still around I saw no noticeable damage boost, just made the numbers show they were criting higher. Not sure what the deal is but I've been living with this nerf for a while. Would be nice if they touched up contagion a bit though after the eclipse nerf to make it more competitive.
I've been playing around and while it's noticeably weaker and cant nuke higher armour enemies like it used to, I've been playing netracells and it still largely ohk everything. I'm now in the process of turning all my red archon shards to purple to get the extra double crit damage buff.