1. Most people not expected.
This is wrong because if it's a NEGATIVE, you must use the word didn't (or "did not") + the PRESENT TENSE
I didn't go to work yesterday. I went to work on Saturday.
The cat didn't eat his food. The cat ate some grass, instead.
It didn't rain this morning. It rained last night.
2. Most people did not expect.
YES! Here, you used the word "did" PLUS the present tense of the verb.