Removed because they can't add it before d sport gets mib license for hd transmission. So, discovery are sending the channel to dth after downscaling it from their side only. The one d2h had added was not actually the hd channel, it was the already downscaled version(which explains the low pq). Maybe there was miscommunication betn them and d2h thought that they were to add original feed(which they thought to be hd) as well as another in sd. But now its clear so removed the hd.
Because the actual d sport hd, when they were testing had good pq, as Gssran bro already said, and he had even shared snaps in his thread of good pq..