I think the person quoted in the OP is correct insofar as he speaks of a "reassessment" of the timeline of Paul and not necessarily a change in that timeline. But I seem to be out of step with others here, so maybe someone can tell me what I'm missing.
Does not the traditional dating of Paul's letters depend on "pillar apostles" in Jerusalem being the same persons identified in the gospels, and hence alive and active in the mid-first century? Similarly, Paul's references to imprisonment, persecutions, ship-wreck, letter to the Romans -- aren't these related to the time-settings of Acts?
If the Gospels and Acts can be placed anywhere between 70 and 170 ce and if they are fictional narratives, then does it not follow that we are entitled to at least reassess the possibility that Paul's writings are likewise datable any time up to around the mid-second century?
If there is a "historical core" to the Gospels and Acts, and even if they were written as late as the mid-second century, then would not the orthodox time-line of Paul hold firm? Paul would then still have to be a contemporary of the three leading apostles of the Gospels; he would still need to be unacquainted with Rome in the 60s.
(I don't think Aretas needs to be decisive in dating Paul at any period. Paul's letters are replete with such tropes from the OT righteous persons and letter writing was an art that was taught, like other arts, with multiple
fictional exercises. It might be a genuine historical reference but the odds are the same for it being a fiction. Until external or independent evidence comes along the settle the question that's how the odds must remain.)