I'm having a hard time believing that Strahan and Ripa had a bad relationship. I don't think you can fake that kind of chemistry and, whether you like them or not, the show was VERY successful.
I believe that the network wanted to pull that younger demographic toward GMA. It's all about advertising dollars and the show was not pulling in the dollars the way that they needed to. They could pull in Ripa, who would never leave her gig at Live or they could pull in Strahan. They took the latter and kept it from Ripa so that she couldn't use her leverage to get him to stay where he is.
I also believe the network botched the whole thing, horribly. He's not going to pull in the same ratings without that give and take he had with Kelly. That Live! audience is not going to tune in earlier. Kelly will have a hard time finding the same chemistry with another co-host. The public discord is going to cost them viewership because it all looks so petty.
Won't be the first time a network has messed up.
Yeah, I don't think this was meant to "disrespect" Ripa or had anything to do with her relationship with Strahan, although obviously it impacts both. I think the network was just after $$$ and took what they saw as quickest way to get from point A to point B. Whether "point B" was a good business decision is another matter.