Well it looks like Kratos is not completely done in the God of War series. A job listing for Motion Logic Studios lists God of War 4 with a specific job description. Below is the job listing for Motion Logic Studios.
We’re keeping a close eye to this news but Sony will most likely push this to the side with “we don’t comment on rumors” remark. Or just ignore it as I suspect, but one thing is clear, God of War 4 is mentioned and they can’t hide from that bit of news.