Yes, it left the factory in Japan on 19th April and arrived in the UK on 11th June. (About 5 weeks on the ship I think.) Nothing has happened since then! ??

Possibly waiting until at least half a truckload of cars destined for the same dealer.

The cost to deliver cars individually by transporter, ie 11 cars 11 drops, would be very high, yes road carriers usually get a standard fee per depending on various things such as distance but at the standard delivery fee the carrier prepared to deliver to 11 dealers in one trip won't be in business for long plus multiple drops all over the country increases the possibility of transport damage.

If you want the car immediately your dealer could probably get it transported on a single or two car carrier but would expect you to stump up the extra transport costs.

Every new Swift I’ve seen has been built in Hungary.

They aren't always right but, according to Wiki, only two generations of Swift were built in Hungary between 2005 and 2017.

New car is built in Japan (as the OP says), and India by Maruti Suzuki. Previous model was built in seven different countries, but not Hungary.

Every identification sticker I’ve seen on one says Hungary, but I’ll stand to be corrected.

That is curious. Just found this Suzuki UK press document for the new Swift, it says they are made in Japan (for UK, Ireland and Europe)

all-new-swift-hybrid