2.x: anon.random_string returns null whereas before it would always return text

The anon.random_string function in version 1.x always returns text even when length = 0.

With version 2.x the function now seems to return null if length = 0, this caused my pipelines to break because of not null constraints on columns using random_string as anonymization function.

I can obviously work around it using ternary for eg but I'm wondering if this BC break is intentional.

Thanks!