It's hard to say, but there's a few possibilities:
1. He won't rage at all. Instead, he'll pretend to have depression over it and let his autistic fanbase do the raging for him.
2. He'll find someone to blame. Who will it be? Casey Alexander? Seth Macfarlane? Viacom? All of the above? Whoever it is, every video he makes afterwards will be full of hateful rants and thinly-veiled death threats towards them.
3. He'll go to Wal-Mart and vandalize the Spongebob DVDs, pepper spray the manager, and demand they don't call anybody.