Looking at this logically........
WMIIC (WMI INVESTMENT Corp) IMO was the main sub of WMI that was responsible for and holder of WMI's Investment interests.
These interests would include ALL interests the Holdco held in Trusts, ABS's, MBS's and other various Income Generating Vehicles.
This means that WMIIC was, apart from WMB obviously, WMI's "Crown Jewel" sub as evidenced by it's own separate bankruptcy filing.
If these Trusts were actually direct subs of WMI, then IMO they could have been jeopardized during the bankruptcy process.
As an entity in which WMIIC held interests or as an independent SPE of WMI/WMIIC, this would have isolated the assets from Creditors.
Based solely on this, it would be very unlikely that ownership of these Trusts would have been transferred to WMIH upon emergence.
IMO, WMIIC ""owned/controlled"" these Trusts on behalf of and for the sole benefit of WMI and NOW the WMI Estate/Tracking Markers.
This is why I believe there was a Turnover Action, WMI v WMIIC and the LT claimed ownership of WMIIC's assets in an SEC filing.