"Not Now/Confirm" not enabled on all spells

Reyemile

Most Spell cards have a "not now/confirm" window pop up before you cast them. However, others don't. I'm not sure if this is a design feature or a bug. Some appear to follow a consistent patter--card draw like Read The Bones and Artificer's Epiphany get cast automatically, while card selection such as Anticipate and Talent of the Telepath do not. However, other cases seem to suggest that this is a bug, not a feature. For instance:

Displacement Wave has a confirm window, but Crush of Tentacles does not.
Remorseless Punishment asks for confirmation if your opponent controls a creature, but is automatically casts itself if your opponent controls no creatures.