Why should they change? They won last time, and the demographics haven't changed radically in four years.
They don't need to adapt in policy. They can simply adapt in the mechanics. They've done their best to exclude those demographics from the ability to vote. Should any of those exclusions be questioned, they now have a large majority of justices to affirm that they are legal.
It doesn't matter that they're a majority. The circumstances have been rigged to allow a minority to rule, and having done so, to continue to set the circumstances to entrench that power. That move has finally become complete and it doesn't matter what millennials want.