Boca Chica is a test facility. SpaceX is only allowed 5 launches of the StarShip second stage, and 5 launches of the full stack each year (page 17 in [1]). More frequent launches will require a new environmental review. They plan production launches to occur out of Florida, and have already begun permitting and building of a launch site there.
They've built Starbase there, with all the rocket assembly facilities and the new expansions. Unless they're planning on shipping all the rockets via barge, I think it's safe to assume they'll send them to Florida by launching from Boca Chica.
They're building factories at Cape Canaveral too, the Starbase facilities have been designated as prototyping facilities. Any changes to production would be made , tested and optimized there first, then brought over to other production facilities like Cape Canaveral. Although initially they might still have to transport boosters and ships via barge to the cape.
The facilities at Starbase are far more than prototyping facilities. If that were the case, they wouldn't have needed a Megabay and be almost completely finished building a second. They would have just stood pat with the High Bay etc. Same with the new buildings replacing the temporary tents. Starbase will be cranking out LOTS of boosters and Starships.
When I say prototyping facilities, I mean as prototyping for the other factories. As Musk has previously said, since they want to mass produce Starships and boosters, the challenge is to design "the machine that builds the machine". That's why I mentioned changes to production being tested and optimized there rather than changes to the vehicles specifically.
Has Musk, Shotwell or anyone at SpaceX ever said that this was the case? I haven't seen any sign of this at all. And again, if Starbase was just for prototyping workflows, there's no need for two Megabays.
Why not ship by barge? It'll be far cheaper than the fees, costs and labour costs associated with a rocket launch. Both Brownsville and Cape Canaveral are well set up for barge shipping.
Also, they're expanding their factory in Florida, so they could be built on site.
There's that protected-from-open-ocean barge lane (I forget what it's called?) that I think runs right from Brownsville to Cape Canaveral, or close enough, I think they plan on using that.
Sure you could ship by barge. It's just that SpaceX has never said that's the plan. Looking at the expanding factory footprint at Boca Chica, it's obvious that this isn't just a test facility, but a production facility. My hunch is that the current limits of 5 per year will be expanded once they prove it "safe" to launch from the site. They'll boil that frog slowly.
While you maybe be right, I just want to note that SpaceX isn't just expanding factory footprint at Boca Chica. They will be manufacturing Starship in Florida as well and have already started expanding there too.
They've pretty much scrapped their initial plans to use old oil platforms for launches, and the size of a barge needed to launch (and retrieve the first stage) would be tremendous. That idea is a complete non-starter.
[1]https://www.faa.gov/sites/faa.gov/files/2022-06/PEA_for_Spac...