It's an interesting idea, the biggest issue is that the BLD pathogen lives in leaf tissue and most nematophagous fungi dwell in soil or woody stems. If an endophytic fungi were found to have an adverse effect on nematodes, that might be the key to making this work. See 'phyllosphere microbiome' research for real attempts at doing this sort of thing.
This is part of the issue with the invasive Golden Oyster in North America, their mycelium paralyze and kill nematodes very efficiently which (directly or indirectly) leads to outcompetition of native fungii.
https://news.ycombinator.com/item?id=47536102
These folks must really have their hands full with the 3M+ pages that were recently released. Hoping for an update once they expand this work to those new files.
This is nuts. If I'm understanding correctly, the M. ibiricus queen mates with a M. structor male, uses his sperm to create sterile, hybrid female worker ants for her colony, then she (astonishingly) can also lay eggs that develop into fertile M. structor males, which means she has removed her genetic material from the egg and effectively cloned the male she previously mated with.