The MSM have been using ‘informant’ everywhere. Informants are associated with law enforcement, catching bad guys, and preventing crimes. Good things.
Trump is using SPY (uppercase). Spies are associated with stealing information, targeting an enemy, illegal activity, etc. Bad things.
SPY is easy to remember. Next he invents the neoligism SPYGATE. That’s easy to remember too.
As Scott Adams would say, this is smart persuasion.
James Clapper’s tweet using SPY (uppercase) was colosally stupid. Thanks to clapper, Trump is going to use the word SPY and beat it like a drum.
It's a lifecycle thing.