It's unclear exactly what Apple meant by this. It could simply be cautioning Brewer that any such change could mean issues -- not necessarily even connected to Apple -- in the future. Or it could be a threat to remove the partially-built sapphire glass plant from its plans.
The measure was passed in Arizona's state legislature last Thursday. Since then, Brewer has faced pressure from national Republican party sources to veto the bill. In fact, three state senators who initially voted for the bill have changed their minds and are now asking Brewer to veto it. The measure, which passed the state Senate 17-13 in a party line vote, would have failed had those three voted against it.
Arizona's two U.S. Senators, John McCain and Jeff Flake and both Republicans, are also asking Brewer to veto it.
In addition to Apple, American Airlines and Marriott have warned that an anti-gay law could be bad for business. The NFL also has not ruled out moving Super Bowl XLIX to a different state, should the bill be signed into law.
To be clear, the bill is being portrayed as anti-gay, but it is written is such a vague manner that it could be used by anyone to refuse service to any group of people, as long as they cited religious grounds. One could imagine SB1062 being used to refuse service based on race or religion, for example.
We don't know who at Apple telephoned Governor Brewer, but it is said it was definitely not CEO Tim Cook. Exactly what was said is also unknown.
Brewer has until Friday to sign or veto the bill. She could also do nothing, which would make the bill law.