No, it's under review with D-Link and one last FW update should be forth coming before EOL from what I'm told.
Who told you this? The customer support rep I spoke to said they were aware of the problem but that they were not working on a fix. It sounds like you are speculating.
The problem is only seen with ISP speeds 100Mb ISP speeds. Users with 100Mb ISP speeds and above should disable QoS until further notice.
I'm not sure how you came to believe this, but my connection is only 55 Mb and I have the problem.