It shouldn't be that unexpected a development. After all, Pakistan imposed punitive costs for the "pragmatic and sane" behavior shown by successive governments in India. And as with humans (or animals), behavior with punitive costs are quickly rectified.
Pakistan may choose to deny the Indian version of the narrative, but the fact is that the nation has learnt lessons, or rather learnt of the consequences for appearing weak, meek. And those lessons aren't going away anytime soon.
26/11 was the actual tipping point. Previously, there was actual hope that the entire spectrum of problems may be resolved as there was a lot of backchannel negotiations in progress. But whosoever and for whatsoever reasons perpetrated 26/11.. effectively ended any chance of peace within the two nations