Die Oberklasse

I am about to purchase a 4K Blu ray player most likely the new Sony model. One question is if when connected to my Connect TV will the TV automatically alter its contrast/brightness settings when it detects a HDR video input.

I do seem to recall somewhere that brightness settings are increased with HDR playback

This is not a question of contrast and/or brightness settings but rather a question of the source interpreting the HDR capabilities of the tv set properly and signalling HDR content correctly via AV info frames in the HDMI signal. If either one fails you have washed-out video because of the completely different tone mapping (EOTF) in SDR and HDR.