Great news if the start moves.
Well more the end.
The velodrome was not a great end to the ride in 2015, yes it was passing it down, but there was nowhere easy to go watch riders finish and cheer and jeer.
Many hotels won’t have their bookings open for the month of August 2019 yet, so I am certainly not going to worry about it all. I stayed in Versailles itself last time. Much nicer than being near the start, some great restaurants etc. and then some big old house to look around.