There were no roadblocks on the highway to Colon today or during the weekend. The company responsible for managing the highway regularly posts updates on their Twitter account (https://twitter.com/ConcesionariaMC). I visited Colon last Thursday, and the road was temporarily closed by the police until 6 pm, likely to prevent cars from getting stuck on the highway and to reduce the risk of robberies. Once the road reopened, the traffic flow was smooth, and I encountered no issues in the city.
My current plan is to travel Saturday morning to the port. If everything is ok, it should be around one hour drive from Panama City.