An Engadget interview at last year's CES was the only source I ever saw that the 2015 models would get updated to 6.0 and that wound up happening for what it's worth.
I'll believe it when I see it. I'm actually quite surprised that I got Marshmallow on my 2015 Bravia. Hope this is true.
Sony was always good with updates at least with their smartphones. Not always the fastest but at least they got updated.
I saw something similar on the [sony community forum] ( http://community.sony.com/t5/4K-Ultra-HD-TV/Why-are-no-journalists-at-CES-blasting-Sony-for-their-total-lack/m-p/611094#U611094 )
I confronted Sony about it [no marshmellow update]. They told me Nougat is coming to address most of the issues on the D line, but they also told me not to quote them.
I didn't see anyone else reporting this. No time table mentioned. Take with a grain of salt.