Does Paul intend that what follows after 1 Corinthians 7:25a have less authority?

We miss the point if we understand that Paul's advice is that a single person should remain single or get married depending on circumstances.

His 'inspired' advice is a commentary on the command to "be fruitful and multiply". Paul is saying that fruitfulness and multiplying does not refer to bearing children in the flesh, but in serving Christ.

He suggests that marriage may be a distraction from serving Christ, and not being married may be a distraction from serving Christ.

Christ's own example is that as a single person he was fruitful through his total devotion to the Father even to death. And from the types of Christ, (Adam, Seth, Noah, Abraham, Jacob, etc) that the Christ type and his bride were fruitful together.

He advises to take the decision to best serve Christ in order to be fruitful. His 'wisdom' is taken directly from the Torah understanding that the purpose of the law is to point to Christ. The purpose of the command to be fruitful is to point the bride to Christ so that together they are fruitful.