Those are actually not prefaced at all. The faces are indeed generic in design, but any face with a date code on the Ace of Spades isn't prefaced!
Prefacing is done with Congress decks because they typically come in a variety of designs - some are regularly reprinted while others change with the fashion of the times, so the common practice was to pre-print the faces without a date code on the Ace of Spades, then print the backs when they'd settled on what designs they wanted, thus saving time by being able to pre-print the fronts even before the back designs are completed.
On the other hand, Aviators generally don't have any unique back designs, just the basic, bland-looking design for their poker-sized deck and a similar design for their (now out-of-print) bridge-sized deck.
There were many other inexpensive brands that USPC acquired over the years, low-end names like Mohawk, Caravan, Torpedo, etc. - instead of printing unique faces for cheaper brand names, they used to all get the same Aviator back decks in them. I'm just guessing, but it's possible that they might have been using the generic faces for some of these decks and apparently the Aviators themselves were also getting the generic treatment for a while, though I couldn't tell you the precise time frame for when all of this happened. Over time, USPC stopped making the tucks for the cheap brands, discontinuing them completely, and now the unique Aviator faces are all that you will typically find.
I personally have two packs of Torpedoes with sticker-type USPC seals on them and an AoS date code that makes them from 2003 - they have fully-standard Aviator faces as well as backs. I'm certain of the date because the ad card has their website on it, so it couldn't be any older, and the date code "E" hasn't been reused since. I also have two pack of bridge-sized Aviators printed for sale in Canada by USPC and sold as "International Playing Card Company (IPCC)," with IPCC sticker seals. One (my red one) has an E date code on an AoS that indicates IPCC origin and US manufacture and a website ad card, so it's also a 2003 deck, while the other (my blue one) is older, with an R date code - that plus the lack of any Erlanger markings (they say they're made in Cincinnati by USPC on the AoS, no mention of IPCC) indicates they're from 1992. Both decks have generic faces and identical backs, similar to the poker Aviators in their quasi-generic appearance but different in many ways. Aviators have some of the most boring backs I've ever seen on a standard deck, next to the Bee Diamond Backs!
So we know that at least some Aviator decks between 1992 and 2003, possibly more years, were getting the generic-face treatment, while they still had the 1960s-look jet plane tuck box designs. When I was younger (1970s and '80s), all the Aviator decks I ever saw had the jet-style tuck box and face designs, and all the modern Aviator decks I find today (where I can find them) have the jet-style designs. I wasn't even aware of the brand's original prop-plane designs and Charles Lindbergh-related origins until long after I started collecting cards.
I should caution you as well that there was a period in the early-mid 2000s when USPC farmed out manufacture of Aviators and a few of their less-popular brands (Hoyle, Streamline, etc.) to Chinese printers. The practice only lasted about two years because of quality issues - the only deck they farm out to third parties in China today is the Maverick brand, which is a "dollar-store" grade deck to begin with. It will state clearly on the tuck box if it was made in China, so keep your eyes open for that. I learned of all this during a phone call with Bill Schildman at USPC when he was in Custom Division - not sure if he's still there or moved higher up on the food chain.