It would make sense. The low pricing of devices like the Kindle Fire and Nexus 7 are a result of both downsized specs, including screen size, as well as a lack of cellular connectivity. It would make sense in another way: doing so maintains the mini's big brother, the iPad, as Apple's top tablet, with cellular capability dedicated to that tablet line only.
However, the sources also indicate that Apple may refresh the iPad line at the same time it launches the iPad mini. The reason for this would be to incorporate 4G LTE functionality in devices that are outside of the U.S. and Canada.
When the 4G iPad was launched as the third-generation or "new iPad" as Apple calls it, it supported LTE, but only on the AT&T and Verizon networks in the US, and the Bell, Rogers and Telus networks in Canada. Since the iPhone 5 is 4G-capable in the U.K. through Everything Everywhere's 1800MHz network, the sources feel that Apple will unveil a revision of the "new iPad" that uses the same LTE chip as the iPhone 5. In addition, these new iPads would sport the new connector first available on the iPhone 5, and coming on the iPad mini.
This, however, raises a big issue, in that if Apple were to do this, it would basically re-launch the iPad globally. Right now there are two different hardware versions of the iPad in the U.S., for AT&T and Verizon.
The new iPhone 5 also has two different hardware versions, for LTE / CDMA (such as Verizon) and LTE / GSM (such as AT&T). If they launch a new version with this connectivity for the U.K., we would assume they would replace the AT&T version of the iPad ... which means that they either replace both versions or sell one with the old connector and one with the new.
That could prove to be annoyingly complex for both Apple and consumers. Buyers have een critical of shortages for both the dock connector adapter and extra Lightning cables. Only recently have those accessories begun shipping - or at least have a date on Apple's site.
In addition, would Apple want to refresh the line with only about six more months to the iPad 4 (or the new new iPad)? We'll see when the iPad mini launch event arrives.