Is the correct view that the Farewell Circumambulation is Sunnah, based on the fact that Aisha did not perform the Farewell Circumambulation, and that a menstruating woman is permitted to omit it without penalty, and that Aisha's last act at the Kaaba was not the circumambulation?

The preponderant opinion is that the Farewell Circumambulation (Tawaf al-Wada') is obligatory for those who are not menstruating. Whoever omits it must offer a sacrifice (dam). The evidence for the opinion of its obligation is found in Fatwa 112276. Ibn Qudamah refuted the argument of those who deem it merely recommended, based on the concession granted to menstruating women, by stating that the specific exemption of menstruating women from performing it is evidence of its obligation upon others. As for citing Aisha's non-performance of the Farewell Circumambulation as evidence, there is no proof in it. Ibn Battal transmitted a consensus that if someone performing 'Umrah circumambulates and then departs, that suffices for the Farewell Circumambulation. Aisha's hadith is evidence for the permissibility of combining the obligatory circumambulation (Tawaf al-Rukn) with the Farewell Circumambulation.