I believe that it is VERY, VERY common for autistic folk of any age or background to have atypical forms of communication......so I really don't think that your seven year old's current style is anything to worry about - at all.
I happen to be an autistic soul who can communicate in a plethora of communication styles, including the jargon filled short sentences that you mention above.
My default communication style here on this forum (these days, as a 50+ year old) tends to be very florid and wordy. However, in real life, my style of communication can change instantly .... depending on my mood and whom I am speaking with .... it used to scare me ... and it still unsettles other people !! I am a very good mimic.
May I ask......what "type" of jargon does he speak in?
I'm neither joking nor exaggerating when I say this.....that could be a description of me at work (which i deem playtime, these days.)
Thankfully, I have skills and competencies that allow me to get away with it and enable me to pick with whom I work (mostly.) Yes, I'm lucky.....but very often work alone anyway....and yes, talking to myself just the same...all kinds of mental nonsense.
Listen, I'm as mad as a hatter to the untrained eye and ear, quite regularly.
I can shut-the-hell-up when I'm told to [although that's a whole nuther conversation in itself]
If he is happy and not causing harm.....let it roll. That's my feeling anyway.
