As Apple’s September 10th iPhone unveiling approaches, we’ve heard that Verizon Wireless is blocking its retail employees from requesting vacations between Wednesday, September 18th and Sunday, September 22nd. Based on Apple historically shipping new versions of the iPhone about a week and half following the unveiling, it would make sense for the new iPhones to arrive for customers on Friday, September 20th.

Due to the high demand and interest in Apple’s smartphones, it is likely that Verizon Wireless would restrict vacations during that timeframe in order for as many customers as possible to be assisted and sold new iPhones. T-Mobile USA, Apple’s most recent major U.S. carrier partner, and AT&T are both reportedly also restricting vacations for the same timeframe.

We cannot confirm that these vacation restrictions are for an iPhone launch, but given the high-profile of iPhone launches and the timeframe, it makes sense. It is worth noting that a slew of new Android phones will arrive in September in conjunction with IFA.

At its September 10th event, Apple will likely debut an “iPhone 5S” with a fingerprint scanner, new camera features, gold color option, and improved processing. In addition, Apple is said to be preparing a new “iPhone 5C” that is essentially an iPhone 5 wrapped up in different colored plastics. With the “iPhone 5S” retaining the iPhone 5’s design, and the “iPhone 5C” retaining the iPhone 5’s internal specifications, the question arises: what will happen to the iPhone 5?

It would make sense that Apple would diverge from its typical process of retaining the previous year’s iPhone and  remove the iPhone 5 from its fall 2013 iPhone lineup. Analyst Ming-Chi Kuo, who has provided accurate Apple-related details in the past, seems to agree. The analyst recently said that the iPhone 5 will be replaced with the aforementioned iPhone “5C.”

Perhaps corroborating this is word from Verizon Wireless sources that inventory for select iPhone 5 models is constrained. Specifically, we are told that both color options for the 32GB and 64GB iPhone 5 models are low in stock. However, it seems that the 16GB model is still in supply. It’s unclear if Apple will be retaining the 16GB iPhone 5 when the new iPhones launch, but it could make sense.

With Apple rumored to be doubling the size capacities of the iPhone 5S (all the way up to 128GB), it would be practical for Apple to offer an entry-level 16GB configuration. Perhaps this 16GB will be the iPhone 5. It would not be unprecedented as Apple has conducted similar strategies in past years. For example, when the iPhone capacities were doubled with the iPhone 4S, Apple released an 8GB version of the iPhone 4 to be a low-end model. Apple also keeps around a 16GB iPad 2 as an entry-level configuration to full-sized iPad.

Nonetheless, it appears that Apple’s new iPhone line-up will be mostly comprised of the new iPhone 5S and plastic iPhone 5C.