I recall being aware of A5 not being very strong and that fact not being much of a secret. But there’s a difference between using something known to be weaker t

I recall being aware of A5 not being very strong and that fact not being much of a secret. But there’s a difference between using something known to be weaker than something else and using something that has been deliberately weakened in a way that allows compromise of that channel with that knowledge - which seems to be the suggestion in this article? At that point it’s not weaker crypto, more a back door.