Oh wow, this is not the only thing axed from curriculum. This article goes in some more detail:
https://thewire.in/education/h-for-hindu-rashtra-is-a-ration...
That article barely explains anything and is literally tagged as 'humour'. Looks like they're more interested in playing politics than discussing the changes.
The primary reason cited for these changes is that they're aimed at reducing the burden on students. They've tried to reduce the syllabus by about 30%.