I'm discovering that customer loyalty seems to account for little at Apple these days, although depending on the representative you speak to it can sometimes help influence their decision personally.
I had a defective power adapter replaced as a "gesture of good will", but service declined for a MacBook Air battery that started failing (<80% FCC) within the 12 month Apple Limited Warranty. Eventually an AppleCare senior advisor issued a warranty exception to get the Apple Store to move on what should have been covered to begin with.
I received a replacement Logic Board and Top Case under warranty exception for my 15-inch Mid 2012 MacBook Pro recently because the labels on the board were misprinted from the factory, essentially a minor manufacturing defect that was being silently recalled. Consider that one a stroke of luck.
I've seen customers come in with machines in immaculate condition just outside the 2 year Australian Consumer Law warranty with defective MLB memory being declined, but customers that have dropped or spilled water on their computers covered under a warranty exception. Computers with known issues that would otherwise have been covered by a repair program declined service because they're days outside of the coverage window, but smashed iPhones covered because it's a gesture of good will on Apple's part. The customers that are entitled to a repair with a valid reason aren't necessarily the ones that get covered. It makes zero sense.
AppleCare support agents also seem to have a tendency to send customers into Apple Authorised Service Providers with the expectation set that their iPhone will be repaired or replaced on the spot, when it's Apple's own corporate policy that only the Apple Retail Store can offer a same-day in house repair or replacement. Needless to say, customers don't like driving 45 minutes to be told that the information the AppleCare support agent provided wasn't correct.
So I wouldn't consider receiving good customer service these days a matter of loyalty as much as luck, depending on who you speak to on the day and what mood they're in.
If they do however take brand loyalty into account, it's the individual rep personally acknowledging your product history rather than adhering to some unspoken corporate policy of rewarding customers with a long history of purchasing Apple products. As far as I know, no such policy exists.