It's not that strong early game
Shaco's winrates were often built by mains in the past. If it's 52 right now and he has a low play rate, then this shouldn't be too bad. However, I'm not sure what his pickrate is right now. Shaco isn't top tier right now since the meta favors low economy junglers, I don't think this will push him over the top. A challenger jungler called tarzaned made a tier list recently. One of his tier lists before put Shaco at S tier with Ivern and highlighted his bruiser build. If I remember correctly, Shaco is about Lee tier, meaning he's not problematic. He's unhealthy (unlike Lee) but not problematic
On most jungle camps autoing would often do more damage than using E. The exceptions would be red and blue
In a gank it barely does more damage than an auto if I remember correctly. Now it will actually do more than tickle like how it used to
The buffs aren't a bad thing. I played a damage build for the first time in a while. As of right now assassin Shaco's burst feels somewhat underwhelming and the bruiser build is even more brain dead than Annie
The buff will ruin AP Shaco's damage, Shaco's objective control and his damage to tanks, in theory. It also makes him easier to itemize against
In conclusion, don't worry yet. PBE changes aren't guaranteed to go live (for example the Riven "edge" resource change was busted as fuck and scrapped) and we don't know if this is going to break Shaco