Trump will do all he can to make Biden's life hell and create chaos. There will be no unity because McConnell wants none nor do most elected Republicans. The way they will view this is as a weakness in Biden they can exploit and they will use it against him and the Democrats. 

Biden wants to do this not just to appease Trump supporters but also to give cover for all the absolutely horrible behavior from elected Republicans under Trump. It's a mistake because all that will happen when the Democrats extend this olive branch is the Republicans will take a blow torch to it. 

The only way to deal with these corrupt Republicans is to punish them. That's actually all they will understand. If you don't they will then proclaim they did nothing wrong and they will go even further over the line. 

And I am not saying this because I just want to see them prosecuted, I have heard this from Republicans.