Hi,
the migration guide should get an additional topic for the newly introduced method Object>>#initialize (in 8.0.2). The method is implemented empty, so there are no functional changes compared to previous Smalltalk versions, and generally you don't need to take any action. But if you use static code analysis (as we do for our daily builds), you may get a lot of additional "missing super sends" errors now, because all direct sub classes of Object should now call the super implementation in their own implementation.
Ciao, Michael