Why does it say "va'Ya'alu Ito"?
Malbim: I explained (to 41:37, 41, 44) that Pharaoh elevated Yosef in three stages, one after the other. First he authorized him over the royal house; then to be an officer over Egypt; and finally, to be second to the king. 1 Each time he ascended, he kept the previous levels. Since he was over Beis Pharaoh, "Avdei Pharaoh Ziknei Beiso" went with him. Since he was over Egypt, "Ziknei Mitzrayim" went with him; and after them, Beis Yosef, his brothers, and Beis Aviv. Also refer to 50:9:1:3.
Ha'amek Davar: Due to the honor of Yosef, they went by themselves. This is why it mentions Avdei Pharaoh before Yosef's brothers, for Avdei Pharaoh went due to Yosef's honor. 2 This is like when Moshe went to Dasan and Aviram - "va'Yelechu Acharav Ziknei Yisrael" (Bamidbar 16:25), for Moshe's honor, lest he go alone. "Ito" (as opposed to Imo] teaches that they were not equal. Yosef was distracted with his pain and the matter before him (i.e. Yaakov's burial).
Above, Malbim (to 41:44) said that the final authorization was to run the country alone, without asking Pharaoh or other nobles.
Harchev Davar: It was honor of the Mes, even though they did not intend for this, like I explained above (35:8). Even if one cries over the Mes for his own need, or follows the bier for his own need, it is honor and a Mitzvah, and he is rewarded. A Mitzvah Lo Lishmah is considered a Mitzvah. Any Chesed done, for any reason, is a merit. Also a Midrash (Tanchuma Beshalach 2) proves so. With Yaakov came Avdei Pharaoh and Ziknei Beiso, and with [the Aron of] Yosef came the Aron, Shechinah, Kohanim, Leviyim, Kol Yisrael and seven Ananei ha'Kavod. Not all went in order to accompany Yosef's Aron, but still, it is considered honor for him. Once, people mistakenly engaged in a Rasha's burial; that honor was his reward for a merit (Rashi to Sanhedrin 44b. However, the Ramah and Ramban explain differently.)
