I think not.
All of those seats remain in Dem control thanks to the election being won before the revelation. The MSM NEVER instigates these stories with a Dem member in good standing before an election, and every decision is run by the Dem party heads first (as we saw examples of with NYT reporters looking for Podesta's blessing before releasing their stories). There are multiple examples of the MSM having information and holding it when it affected a Dem.
In every case, the political calculus was in favor of the Dems. Sometimes, the story leaks out from a blog or Fox, or some other nonMSM site, and the revelations are a threat to the voter base of the party (like Al Franken or Northam) which forces the MSM's hand. In other cases MSM NEVER instigates these stories with a Dem member in good standing, and every decision is run by the Dem party heads first (as we saw examples of with NYT reporters looking for Podesta's blessing before releasing their stories).
The media collusion (hey here's collusion for you) can be easily seen in the identical parroted phrases that occur with every big story throughout the MSM. They receive their talking points, and then they do their job which is to be Pravda for the Dems.