Adding 'language-highlighting' tag to a question, necessary?

Question

Consider this question.

I provided an answer with a bash script. I did remember to add embedded Prettify language hints. The highlighting didn't get turned on. Then I found this post on Meta SE explaining changes to syntax highlighting.

So I edited the question to add the [bash] tag. Now I'm wondering:

1. Is that a good idea, adding a tag when the question doesn't explicitly limit the solution?
2. Is adding a tag really necessary to turn on syntax highlighting? Remember that I've peppered my answer with language hints.
3. The 'preview' of Q & A (prior to tag-change being approved) still didn't show syntax highlighting. Is that by design?

Answer 1

Your language hints had a typo ("languange" instead of "language"), hence the syntax highlighting didn't get activated.