Because that does sound to me like the original claim was wrong?

I don't think so. At least in my reading, it appears both of these things can be true at the same time if you ready carefully:

Lumina likely aren’t following the Best Practices Guidelines for Probiotics, which require you to state how much of each strain in CFUs is in each batch that you send out on your packaging.

Lumina’s manufacturing process follows legally mandated GMP protocols, if not the probiotic trade association’s voluntary best practices.

These are saying the same thing - it looks like the probiotic best practices aren't being followed, but they appear to not be legally mandated.