In regard to your inquiry, as you mentioned above since you are using a 6th generation processor, you can always install the [15.40] drivers to be able to use the usual features.
For the 7th generation processors I just wanted to let you know that Intel is currently working in developing new graphics drivers for those processors, those drivers will include different features that might include the usual features, at this moment there is no official release date for them yet, but it will be any time soon.
Also, as you said before, there is no official statement from Intel saying that some of the previous options will be accessible on the new drives or not, so at this point we will need to wait for the new drivers to be available in order to confirm that, please keep checking our web site for future updates and drivers releases:
We really appreciate your feedback, and I will transfer your suggesting to the proper department for them to be able to see your comments on this matter.
Any further questions, please let me know.
This message was posted on behalf of Intel Corporation
First of all, let me apologize for any type on inconvenience.
I just wanted to let you know that we really appreciate the feedback provided by all the peers in our communities.
In regard to your request, I already sent this report to the proper department, hopefully the option will be back if there is a newer driver release, there are a lot of users that want the gamma option back as it was before.
I just wanted to check if the information posted previously was useful for you and if you need further assistance on this matter?
Any questions, please let me know.