Heck, Mab was *not* subtle about claiming Harry. And he immediately charged into Chicken Itza alongside the Leanansidhe.
However he didn't really have any good options, it was the least bad of the lot. However the questions that should be asked is does anyone know....
1] Harry's spine was broken, the Red King was about to kill his daughter, his grandfather, and himself. He was also offered very little help.
2] Uriel told him as long as he was motivated by love he would never stray so far that he couldn't get back on the right path.
3] That Harry reversed the Red King's spell when Susan transformed, thus hoisting the Red King by his own petard..
4] That Harry attempted to suicide to avoid becoming Mab's Knight. That only the intervention of Mab and Uriel with help from the island and a parasite in his head keep him slightly alive.
5] The seven words that Uriel spoke to him that if he keeps to them will prevent him from ever becoming her slave...
Answer, No, they don't, and I am not sure it would help if they did.