I have yet to see one plausible reason for why this would affect primary voting in any way. Voting is done at the local level on local hardware; we don't vote on Facebook.
That being said this year's primaries have got to be historically uncontested that it could not matter less.
Grassroots organizers use FB and messenger and Insta for “get out the vote” communications. People use these services to goad their friends to go and vote. People use FB as a search engine to identify their polling place.