The fact that TNDOT has no intention of co-signing TN 385 over the N-S I-269 segment certainly creates a navigational mess for local drivers; one of the two remaining TN 385 segments -- preferably the less-utilized north segment -- should get a new state highway number.
Or the southern TN 385 could just be renumbered as I-22. 
Seriously, though, I'm skeptical about 269/385 being a navigational mess on two or three counts:
First: it's Memphis, where major streets have a tendency to change names seemingly at random.
Second: in local media, the southern 385 has been referred to by name rather than by number, to avoid questions about which segment of 385 is being discussed.
Third: don't most people rely on sat nav apps these days when navigating to unfamiliar destinations, reducing highway numbers / street names to being mostly just visual cues on exactly where to turn?
It might not be a navigational mess for local drivers accustomed to local vagaries or departures from norms seen elsewhere -- but to "newbies" or those simply attempting to navigate the area while visiting the presence of two segments, east delineating a E-W freeway, bearing the same number might become confusing. And that isn't a condition that would likely be programmed in apps; distinguishing the "north" section of 385 from the "south" section would likely throw such into a bit of a tizzy if not pre-programmed to recognize landmarks or mileposts or interchanges from one another.
While I like the idea of the southern (Collierville) segment of 385 becoming a I-22 extension -- the lack of a direct SB>EB flyover ramp at the 22/269 interchange is a negating circumstance (nobody needs a duplicate of the I-80/I-74 cloverleaf in IL, with
two trunk routes schlepping through a low-speed single-lane loop). But then TN has built
both of its freeway-to-freeway junctions (save the I-69/MS 304 separation east of Tunica) as cloverleaves -- so "cheaping out" (although the 22/269 involves 4 individual bridge structures to accommodate the C/D lanes) seems to be a state or regional priority, likely because of funding shortfalls.
Even out here in tech-happy San Jose, only a handful of people I know regularly depend upon phone-based or in-car navigational aids to get around; and those that do simply locate addresses and use their personal built-in systems (i.e., their
brains) to figure out how to get from point "A" to point "B". Ironically, a couple of apps haven't figured out (or have been programmed to recognize) that there's no direct access from CA 87 to I-880 (it crosses, so therefore it must have an interchange!?), to the surprise of folks coming in from elsewhere (including a number of my customers, who would access my business from CA 87). So, for many, it's back to AAA maps and a decent learning curve!