I would like a source too as I've looked and can't find any source of it being reopened except rumours in 2014 which were denied
As the 20th anniversary of the Nirvana singer's death nears, Seattle police knock down claims that the case involving his death is open again.
www.nbcnews.com
A lot of the current conspiracy theory stuff comes from the documentary Soaked in Bleach, this article does a pretty good job of debunking some of it
https://knowsnotwhatitmeans.blogspot.com/?m=1
As a huge fan of Nirvana and Kurt himself I've looked into Kurt's death a lot, read his journals and watched all of the documentarys and all his interview footage I can find and to me I lean toward it being a suicide.
Krist Novoselic also did an AMA on reddit recently and even he thinks Kurt killed himself, pointing out that Kurt bought that gun himself even though he didn't hunt at all. He also asked that if anyone had any evidence that it was foul play they should go to the police, but I suppose people have yet to provide anything concrete.
That all said, I didn't know the man personally and the only person who really knew Kurt and how he truly felt was Kurt himself.