Unfortunately the Scratch developers have chosen to write Scratch 2.0 in Adobe Flash, perhaps one of the worst mistakes ever, given Adobe are ramping down usage of Flash and it is already deprecated on mobile platforms and Arm.
So it will not run on the Raspberry Pi.
Personally, I find the decision to go with Flash incomprehensible.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
"My grief counseller just died, luckily, he was so good, I didn't care."