Tbf, he was great for Newcastle, prob the 2nd best RB in the league while he was there. I think there was bad blood between him and Wenger. With the rumours around Bellerin, Wenger prob saw no way to bench him, and seeing no future here, Debuchy wanted out but for various reasons, had to wait yrs for it to happen.
I like Hector, but I don't think he's irreplaceable or anything. I suspect we could give the job to AMN and we'd be just fine.