I don't remember it that way at all. He did like Morg at first. Morg was loyal. Morg didn't have morals like Norrin and wasn't ambitious like Terrax. Morg was like a really good herald and Galactus appreciated his efficency.
Morg was happy to be the lackey as long as he was allowed to kill. Galactus was miffed that Morg killed Nova (his favorite or 2nd favorite herald IMO). But Galactus brought Morg back to life very soon after Terrax killed him...so he apparently didn't hold a grudge for that long.
Morg is that employee you may not personally like but you know his work is going to be top notch. None of the heralds were as loyal or as committed to their job as Morg IMO.
I fully admit my memory of that era is not all it could be. Or rather, I was less preoccupied with Galactus and his herald, than the others. Not a huge Morg fan.
However, you have jogged some memories within me.
Yeah, I do remember a sort of, Galactus even wanting a herald he wouldn't get attached to, like previous ones.
Of course this may have been my inferred understanding... it has been a while.