Offhand, there's an asymmetry between Arminian OT scholars and NT scholars. I don't mean Bible scholars who happen to be Arminian, but Bible scholars who aggressively promote Arminianism. Grant Osborne, Ben Witherington, Brian Abasciano and I. H. Marshall are four prominent examples in the NT field. Where are their OT counterparts? What OT scholars are Arminian apologists?
Maybe it's just coincidental, or maybe even Arminian Bible scholars sense the OT is less hospital ground for their theology, so they delegate that to NT scholarship.