He recommended the HHS (overarching org of the FDA) reevaluate the schedule status of it back in October '22. The HHS took like a year to do their thing and then made a recommendation to the DEA to change it to schedule III. The rest of the time from them until now was the DEA also doing their own internal review.
I feel like if the timing was political, they would have pushed this news out to late summer closer to the election. That's not even considering the fact that a simple majority in Congress could have done the same damn thing without any of this beurocracy.
Not really though. Executive orders can easily be tied up and overturned in court. If Congress isn't willing to sign legislation to reschedule it, there will absolutely be enough opposition to overturn any blanket order. He essentially did sign an executive order for this, but it was to order the HHS review and do it the slow way.