I don't
know the answer to your question, how people find out about these things that aren't online. Sometimes it is here on the forum. Some of the FP stores have a "lookbook" showing up and coming items and if you ask to see it the staff will show you. Some have good sources with SAs or managers they have cultivated a relationship with.
EDIT TO ADD: some people call JAX (Jacksonville) a lot to see what is new or have figured out how to look at the drilldown site (where
Coach is getting postings ready to put stuff online). If one puts in the effort there's a lot of info out there. ( I am not that savvy, I just read here!)
But I'd bet you any money those soft Boroughs will make it to production. The Borough bag is Coach's "big" hit right now and I cannot believe the soft Borough won't be the next step since they already have umpteen sizes in the original version, the edge paint, and the tote version.
I have no personal knowledge about this and could be very wrong. Perhaps others here know for sure. But I wouldn't give up hope if I were you.
Personally, I'd rather have a soft Borough than the original leathers. I'm hoping (1) that they hit the regular line, (2) I can see one in person and (3) possibly get one at a discount. That's a big wish if it isn't even being produced, LOL.