When you summon a wolf like that for example :
/summon wolf ~ ~ ~ {Angry:1}
the wolf is neutral and no matter if you tape it like that {Angry:1b}, {Angry:1000b} or {Angry:100}.
The /entitydata does not work either.
MC-127617
The {Angry} tag doesn't work on wolf
Resolved
Invalid
0
the Angry tag requires a target in order to be set to 1/true/whatever, you cannot set a target with a command, as such it instantly becomes 0/false/whatever again.