No that can't be what's happening. You would expect contrast to be lost, not increased, if that was the issue.
8bit sRGB can contain 11.6 f-stops of dynamic range, and it is no longer enough for modern screens. There must be a longstanding bug somewhere. It would not be the first time it happened. There was a chroma decoding bug in almost all DVD players. A very similar issue to this, antialiasing in CGI used to be calculated without gamma, until GPUs got fast enough to use it and I suppose that someone started looking into why it performs worse than expected.