This can be very frustrating when it's a false positive, but these 'neobanks' have a tendency to be very "trigger happy" and quickly close accounts whenever they have a reason to think there is fraud involved. And there's a lot of automation involved of course.

When that happens, they won't tell you the reason of course, because that would help fraudsters improve their fraud skills.

There is no reason to believe this bank actually have humans who are aware of this customer's Twitter handle, and who read it, and didn't like what they saw.

TLDR; this is obvious BS.