Of course there will be some residual "Barker" things, especially in the beginning. It will give Drew something to work off of.
But in the long run: a few weeks, months, or seasons down the road, there will be nearly nothing of the Barker era because it will be solidly Drew's show. Some new games will have his name on them (if they so desire to do that) and he will have his own way to toss to Rich, to the first item, to breaks. He might even have that righ out of the gate.
I'm going to make people mad when I say this, but being a realist it must be said: The Bob Barker era is over. Sets are being reworked, music re-orchestrated. When the 36th Season start, Rich will be announcing Drew name as he walks through the center doors (or enters on the turntable or audience or wherever) and it won't be exactly the same.
The most important thing is they do not change the structure. I could care less who hosts it, what the set looks like.
That seems to be what most of the users here tend to forget.