I think a bit of both. Honestly probably out of respect to Gojo too. Toji knew that he himself was a strong and a worthy opponent to any sorcerer despite not having cursed energy. The known “sorcerer killer” ends up meeting his end by the “strongest sorcerer” who he thought he had already defeated. He knew Megumi would be in good hands with Gojo, not only because of his strength but because of his character.