UPDATE: I just tried to download something from the 3D warehouse so that I could capture the warning message and now it no longer shows the option to download into 2017 or 2018 and the warning I saw before is gone. It was there this morning right before I created this thread so they removed the ability to download into 2017 and 2018 formats in the last hour or so.
The early bird gets the worm but its the second mouse that gets the cheese.