I asked my dealer about the TCR when confirming my car last week, he said to me that normally they hear stuff from VW which they are told to keep quiet on, but right now they have heard nothing about any forthcoming products. I have no reason to disbelieve him.
He thinks (his own personal opinion) that a Tiguan R and a Arteon R are likely to be announced soon before any Golf announcements due to where we are in the lifecycles. But again, they have been given no info from VW regarding anything.