These open sources are fake news without any basis.
DRDO chief has said that Kaveri is complete but it is not having enough thrust for LCA :
http://forceindia.net/interview/sec...development-organisation-dr-g-satheesh-reddy/
This means that LCA gets 85kN from F404 but Kaveri gives less than that. According to DRDO website, it is 81kN. So, this means LCA will not be able to carry 4ton payload with Kaveri and will have to make do with 3.5+ ton.
Moreover, I don't see how these open source fake news went this far as to claim Kaveri as failure when it was clearly said that the dry core of the Kaveri will be use for Ghatak UAV. The core is the main part and if that is complete, the engine is almost done. After burner is having very limited number of parts and hence can't be complicated. Here is the news of ghatak using Kaveri core:
https://www.livefistdefence.com/2017/02/exclusive-indias-ghatak-stealth-ucav-moves-forward.html
If Kaveri was a failure, it core can't be used for any other thing either. So, one of the 2 news is inconsistent. Since DRDO chief has confirmed Kaveri development, it is obvious that the news of junking Kaveri is fake news