I object to the word “new,” though — this has been going on for, well, years:
It is true that some dates do seem to cleave history in two. (Those leaning to the left might point to 1789, 1848, 1917 and 1968 as well as 1989; conservatives may prefer 1812, 1914 and 1945.) But that is a call for periodisation, not compression.
In the cramped room of a single year, the air soon becomes stale. The best historians recognise this. They fling open the windows onto the recent past and open the door to the future. Which leaves you wondering why they would confine themselves to such a small room in the first place.