So, apparently on HPG Outreach it is widely believed that you do, in fact, recieve credit for Assists after disco'ing after you died.
They link to a post
here, and specifically the very beginning of Post #1. It was edited later due to Niko retracting the statements he had made, however there are never any cited Dev posts contradicting this explicitly that I could find.
Here is the thread Niko had originally weighed in on, and later removed his posts.
This is all
old info! It seems like the official forums here have one idea about how this issue works, and the subreddit has a completely different opinion.
I'd love to find out for sure. Personally I don't like the idea that people can run in, run a laser across the enemy team and die in a blaze of greed, and then disconnect to do the same thing in their other mechs (or running through all the trials). I'm not sure why they would have reverted this mechanic, as it seems it did work the way we thought at some point in Beta.