Wasn't he a free agent not a few months ago and WWE showed no interest so he want back to TNA? Now that could have been because of the lawsuit TNA had against the wwe that caused the wwe to pass, but maybe not. I believe Morgan's wife/GF is pregnant, so maybe he'd landed a regular job that will offer a lot more security and health insurance.
If the WWE was interested - I think he could be used as new Raw GM Brad Maddox' body guard/security. But then again Mason Ryan could be used in that role just the same.