Material adverse effects have to be rather large; for instance, the company is actually worth 50% less than it was represented as. Even if the bot count is significantly higher (say, 20%) that wouldn't have an easily provable massive effect on revenue. Twitter still makes what it makes, and it still would be roughly the same in terms of profitability.

Keep in mind that the onus is on Elon to prove to a court that the higher bot count has a large, material impact (on the order of 50% of Twitter's revenue). It's not something that is a matter of opinion, but rather based on his ability to argue his position to the court, for which he needs strong evidence.