So that thread is 11 years old. What is shown in that photo is definitely a 120 V receptacle, not 240 V. Still not aware of a 240 V GFCI receptacle in the US.
There has been no need for a 240V GFCI receptacle until recently, and even now, is there a demand? Typically a 240V device ends up on a dedicated circuit with its own breaker, so you just use a GFCI breaker. So no demand = no production.
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden