Well, you got me to look. Did not see couplers - nice HO models, though.
Suspect you are well aware that Jimmy Hill (No, It's Jimmy Booth!) is the owner of Glacier Park, who was supposedly making the SHELF couplers. A few things to consider: that was a while back, and a lot of stuff has happened between then and now (can you say Corona, and we ain't talking beer!) I think somewhere along the way Alan (who is a much nicer fellow, than You or I) gave up on his O dream because of the cost of track and switches. If I were wealthy (I'm NOT!) I would have tried to help him.
I think we will ultimately see Shelf couplers. (Note that others are now showing interest.)
Maybe someone who knows more than I can start a Go Fund Me for Al. They have been done for a lot of worse reasons!