This is one of those things, and there are many of them, that Elon says strictly for attention, not because he believes it or has any intention to follow through with it.
The fact everyone sees through it, but he says it like he means it, is the truly sad part. Imagine if he also believes he's scaring Apple with this tweet.
The best he can do is slap a logo on a generic Chinese Android phone, and then sell few thousand.
People in Silicon Valley maybe see through it, but I'm sure most people outside of tech are thinking "well he can launch rockets so surely he can create another app store."
