Are healing threat reduction talents actually necessary?

I’ve been looking at talents like:

• Healing Grace (Shaman)
• Subtlety (Druid)
• Silent Resolve (Priest)

…and I’m wondering how necessary they really are in TBC Classic.

Were these mainly important early, or are they considered mandatory throughout TBC?
Do healers actually pull threat often without them?
Are these talents more of a comfort/safety pick than a requirement?

Trying to understand whether the opportunity cost is worth it in practice.