Ask your DM
This isn't a simple yes or no question. The title "would a Raven familiar help me during interactions" implies you are asking as a player. But social interactions in D&D are completely up to your DM. As a player, you can think something would work, but you can't guarantee that, since your DM can think otherwise.
Let your character do the investigation
In the Curse of Strahd, the Barovians and Vistani hold the superstition that Ravens carry the souls of the dead with them
How do you know that? Have you read the Curse of Strahd book itself? As a player, to spoil all the fun?
More importantly, how does your character know? Did he read that in a library years ago? (if so, did your DM ask for an Intelligence/History check?) Did someone say so? (if so, how can you be sure they didn't lie?) Let your character investigate. Experiment, dare, make mistakes, try different things. What makes every D&D game unique, is that every DM can lead the adventure their own ways.
If you are the DM
Let's suppose you ask this as a DM. There are actually several different questions here:
- Should the superstition against ravens affect Barovians' behavior? How exactly?
- How can it be represented mechanically?
- Does the Barovians' superstition affect combat?
How Barovians' superstition affect their behavior?
There can't be simple answer, because people differ, and because the answer heavily depends on how does the DM interpret the setting. As a DM, you should figure it out yourself. There are brave NPCs and there are cowardly ones. They can't have identical behaviors.
My guess that incidentally showing the raven won't help a PC in social interactions with Barovians, but will actually make things worse. Imagine someone incidentally makes you break a mirror in Friday 13th. If you are superstitious, you can be frightened because "breaking a mirror is bad luck", but probably you will be offended and angry in the first place.
Besides combat, how do you force someone to harm the raven? The superstition is against killing ravens, not just watching them. Moreover, in D&D world many people can know what wizard's familiar is. They will know that the raven isn't actually a raven but a celestial, fey, or fiend.
Do the Barovians' superstition affect their combat?
That's actually easy. There are strict rules for combat in D&D. The raven familiar has no "gives an advantage on attack rolls against Barovians" feature in its stats block. Neither Barovians have explicit disadvantage on attack rolls against ravens. As a familiar, it still can do the Help action, but just being a raven doesn't give it more features in combat.
Carrying a raven does not give you advantage on your attack rolls. After killing the raven, an NPC might have concerns for their luck. But that will happen after the combat and shouldn't affect the combat itself.
How can it be represented mechanically?
Instead of "+2" situational modifiers, 5e has advantage/disadvantage mechanic. If DM thinks the situation is more favorable to you, they say "make a X check with advantage", or "make an attack roll with advantage". Advantages do not stack, so mechanically one or several favorable factors all will have the same effect.
Considering Intimidation checks, I'm not sure a familiar would help the wizard. PHB page 175 "Working Together" says that
A character can only provide help if the task is one that he or she could attempt alone.
I don't think a raven familiar alone actually can intimidate an adult reasonable human without attacking him (keep in mind that familiars can not attack).