LENR is still a controversial technology, WF would never invest 50 million dollars without being 100% sure. The claims of Rossi are very specific. Rossi claims that he has a working LENR reactor with a high COP. WF invested 8 months after the start of the 1MW test. Their investment confirms a working 1MW reactor. If there were doubts about the test they just would have waited.
Btw, I don't see WF investing in Brillouin Energy, which is seen by most members here as the most credible commercial LENR enterprise.