People, people people, you are all forgetting of an important thing: Theres only 2 ways to it happen, which the 2 of them are mostly NEVER gonna happen:
1. Mutation
A lot, and i mean ALOT people are mentioning it here, but first, this fungi is on earth for Millions of years, and fungis do not mutate that fast, considering natural selection, it's more likely to they go to extinction than anything happens.
2. Artificial Mutation
This one is more probable than the first one, but it's very impossible as same. I don't think renomated biologists and scientist would genetically mutate this fungi, it would be more to biological terrorism, which doesn't even have basis and enough funds to do it so, and the terrorists are already losing, So i think it will NEVER, BUT EVER, EVER, EVER, EVER, EVER, EVER, EVER, EVER, EVER, EVER, EVER, EVER, EVER, EVER, HAPPEN