Interesting, since this never works. If there is any B gate or bus arrival from Non-Schengen an extra screening for US departures is mandatory. This is the reason, why usually NO flights to the US depart from any B gate.

I do not remember any announcement like the one in your posted link. But I usually got my information as PPB emails and via HON mail, so no need for me to scan the LH webpages for this.