It was always just about confidence for me. The shackles are now off.
This, plus some enlightened person management would have made a difference.
From a strict management POV, people generally perform better when they have the support so that failing is an option....trying to avoid failure (playing conservatively) often means playing less well. So giving players the permission to "fail" and also to take on board player opinion and ideas is all crucial if you want to provide the best chance of doing well. It provides a supportive culture that players respond to.
Now - as others have said, the lack of relegation makes this easier to implement for management/coaches. However, the change has been so material, it does also reflect well on the "interim" coaches
And it doesn't have to reflect badly on Dai. As a number of posters have suggested (me too) all coaching regimes come to an end and from a distance, it look like that might have been the case. So its the biggest of big thanks to Dai and now Wasps need to move on.
The (short term) evidence is that the players have a smile on their faces, they are backing each other up and are enjoying each other's successes. The banter post drop goal, really revealed a team having fun!