I find Apple's pronunciation of "silicon" very strange. I've always heard everyone say "silicon" like they say "silicon valley."
I just went and re-watched the start of the "Apple Silicon" segment, to hear Tim say it again.
FYI, his pronunciation of "silicon" is as neutral as you can get in the English language IMO. I grew up in Australia with first-generation British parents, have worked with North Americans, Europeans and Asians plus a few others (Africans, South Americans) for a decade and a half, and currently live in S.E. Asia - I've heard a good number of accents on the English language.
I'd imagine most British would probably put slightly more emphasis on the "o" so it's "silli-kon" whereas Tim just de-emphasises the "o" a lot - but either way it's a short 'o' sound (like in off or orange or orangutan vs a long o sound like "oh" or "only"). Of course if you add an "e" (to become silicone) I'd expect the brits at least to pronounce it with a long O, line in "phone".
So the normal pronunciation would be "Sill-eh-Kahn," making it 3 syllables long.
Here comes Tim with "Sill-eh-Kun," spoken rapidly, as if it were one syllable.
I'm not sure you're qualified to disparage others pronunciation when you're suggesting there are "a" or "u" sounds in the word "silicon".
It's bizarre and odd, especially when they should just call them "Apple Processors," which is what they are.
And how would that pronounced? "PRUH-cessor?" Or "PRU-CESS-ER". Have you by chance heard the way the word "potato" is said in the game Exploding Kittens (i.e. in the iPhone game, it doesn't make sense in the card game version) and thought "yeah that sounds right"?