According to Musk, Apple has threatened to hold down the number of users in the app store. The news comes after Musk said Apple had mostly stopped advertising on the platform and a poll asking if Apple should "publish all censorship actions it has taken that affect its customers" Apple didn't comment on Musk's claim right away.
There have been signs of tension between Apple and Musk's company. Musk called Apple's App Store fee a "hidden 30% tax" on the internet. The Apple App Store boss deleted his account immediately after Musk took over.
Apple CEO Tim Cook said in an interview with CBS News that they are going to moderate. I expect them to do that. Musk floated the idea of a mass unbanning of suspended accounts.
The boundaries of Apple's App Store moderation have been tested by Twitter and other services to either hide potentially offensive content or ban it entirely. One of the reasons that adult content is still allowed on its app is due to the fact that it is sparred with Apple over certain content.
If Musk is correct, "withhold" could mean a temporary rejection of an update to the app or a more serious threat to remove the app from the store.