hi all, I have a 2020 emonda SL5 and I'd like to update the cockpit to aerobars or something with flatter tops.

Im seeing that most integrated systems are built for wireless drivetrains so this is out of the question. My question is if I upgrade to a carbon bar, I assume I need to change to a carbon stem as well, correct?

Anything I should consider before ugrading to a carbon cockpit?

I appreciate any insight anyone can offer.

thanks!

No - there's nothing stopping you from using an Al stem with a carbon bar - just be mindful of the appropriate torque on the clamp bolts.
Also pretty sure that any number of integrated cockpits will accommodate wired electronic transmissions (I'm making the distinction between "wireless" as you used it and "electronic"). You might have trouble getting a mechanical (Cable-op) transmission to work with an integrated cockpit, but electronic (wired or wireless) shouldn't be a disqualifier - but I could be wrong, I'm a bit of a Luddite.

I have been using a carbon handlebar with an alloy stem for the last 15 years

My ‘23 Trek Emonda SL7 came with a carbon bar and aluminum stem. I assume Trek thinks it’s OK. I like the design of some bars that have a flat section near the stem, but you need to consider mounting options for a GPS type computer, as the usual out front mount cannot clamp on an oval bar. You then need to use a mount that clamps to the stem bolts, or something along those lines.

Frankly, I would bet good money that the vast majority of people with CF handlebars use aluminum stems. Cheaper and lighter usually. Most everyone I know anyway, myself included (3 bikes with CF handlebars)