Being in the news for any reason is the last thing a bank wants right now. With startups and the public so much on edge, a simple "omg look at this, Brex is in trouble" tweet can be enough to cause them serious harm.
My guess is the exact opposite – the announcement was pre-planned and they went ahead with it, but some middle manager is going to be getting an earful for not delaying it until the sector is out of the woods.