True, it's available to all. But they told all of us they would only be using Mersora/KJ as they do in all their stores. They told this to many people many times back when they first opened. If they made the switch, they shoiuld have told people or posted a sign. Why would I look in the back to check when they told me they would only be using Mesora? I needed to be told by someone in the Kashrus field, who alerted me. I didn't even believe it until I checked the boxes myself.
Not currently living in the US but when I looked into it about 10 years ago I believe they did check
They are under a Hashgacha which most who shop there rely on, if you have a particular standard or requirement, the onus is on you...
If you had a severe allergy to an ingredient, would you rely on an employee's information that you heard once upon a time ago or would you check every time before purchasing/eating?