Apple has 370+ stores across the country and 65,000 retail workers. Exactly one store is unionized. It’s safe to say that broad benefits decisions across the company aren’t being driven by this union.
The implication is that additional perks will make other stores less likely to unionize. One store successfully unionizing is certainly enough to cause Apple to take such measures, they're likely trying to prevent a domino effect.
A company of Apple’s size routinely adds and removes employee benefits. It’s not like they offered nothing before a single union consisting of a handful of employees showed up. To make this claim you need to look at a time span way longer than a couple of months to see if there’s an actual correlation.