You're looking at this backwards, this is good for EA. Of course its not going to help Zynga, but its going to clear out the cobwebs at EA and increase their quality. Out of those two producers, the one with greater potential to (and proven record at) creating high quality product is EA. I'm not saying its all been gold, but they actually try, and some of it has even been gold; that's much more than can be said about Zynga. Everyone high ranking jumping ship from EA to Zynga clearly cares more about maximizing profit than producing quality product.
I don't mean to imply that all game designer/devs should suffer for their art, or that Zynga doesn't have people who don't care about the craft, but seriously, this is Zynga we're talking about. The "fast-following", scamming, addict player seeking, facebook feed raping, watered down game developing, Zynga. If someone is willing to go to Zynga, they're probably the kind of person responsible for EA's criticized practices, quality escaped EA in spite of them, not because of them.
I have to say that I have great respect for Zynga. They have overcome their roots in "Scamville" and built a growing business that now looks like the Facebook to EA's Google.
Despite the fact that I don't play any of their games I find myself rooting for their success since I'm very tired of the EA sequel factory.