I don't care Kaiten is gone either. However the choice to remove it is poor.

If the issue was button bloat (supposedly incorrectly translated):
Then consolidating the Single Target and AOE skills that share a cooldown would have been a far better choice. Simply applying the potency of the single target equivalent to the first target of the AOE version would have freed up more buttons

If the issue was "action bloat":
Then reducing the frequency of Shinten/Kyuten uses would have been the correct action. Increasing it's Kenki cost and potency would have severely reduced action bloat far more than the removal of Kaiten ever could.