Their interests are aligned with XTXI as well as XTEX. As part of the refinancing deal, I think the banks and management will agree to re-write XTXI'x IDR agreement with XTEX. Lots of things have changed; so should the IDR agreement, or so it will be argued. Who knows, maybe they'll merge the two?
You're assuming that XTXI has the ability to rewrite its contract with XTEX. I don't think it does. It can propose such a change and have it voted on by the unit-holders of XTEX. Don't know how far that would get!
They could likewise propose to combine XTXI and XTEX (into XTEX), which would require a vote of XTXI shareholders and XTEX unitholders.
The second is more likely, but being second in this case isn't a high hurdle to jump.
You're correct--I am assuming XTXI can get XTEX to re-write the IDR agreement, or two reasons. First, XTXI owns 33% of XTEX's units, enough to control it. Second, the lenders may require it--or a merger of the two--before they agree to a re-finance. The bottom line is that management and the lenders are in control, the rest of us are just along for the ride.