IMHO, that question can never be answered unless Intel gives the go ahead
but if you were to follow a trend with high end enthusiasts, their market and the components in that segment then there is about 1+ years of life left in the platform unless someone comes along and brings DDR5 to the table or Intel decide to add native USB3.1 type-C/thunderbolt support.
You need to understand that the enthusiast platform introduces all the high end features and is later watered down to the mainstream market.
You're welcome
If this thread has no further queries, I'd like to close it.