Bethesda knows support for the official remake would go down the toilet if they did anything but praise for the unofficial remake. Its hard to take Bethesda on good faith on this.
In any case the corporate entity as a whole is not conscious. A strictly behavioralist approach is appropriate there. If it does the good thing it gets the carrot, if it does the bad thing it gets the stick. We can't win it's heart and mind because it has neither, so we have to settle for keeping it's behavior in line.
The moment such a project might affect sales in some way (that i am unable to imagine right now, but is possible surely), they will backpedal and find ways to take it down.
A friend and old-school RuneScape player told me he was quitting over this: https://www.ibtimes.com/runescape-devs-backtrack-hd-mod-ban-...
Bethesda signaling their blessing might not have happened if others hadn't made such spectacular messes of their own relaunches.