That's a concern. Typically most off the shelf SSD have provisioned so much extra bit error rate / spare that they don't show reduction of life till at least a few years in. I am not sure what Apple did to their own SSD other than they are Anobit based and in theory they are commercial grade capable, and Apple are familiar with every single NAND manufacturer's chips out there and shouldn't make beginner's mistakes in their design.
I hope they come up with some workaround (i.e. a USB-C external SSD for swap memory they provide you free of charge, or reserve 3x the amount of blocks and use them as SLC swap, that will last well into the 100k cycles instead of 5k in TLC) or extended warranty for people who need to replace them early. This is yet another reason I refuse to buy a machine with SSD and DDR soldered.
To be honest, I don't know what Apple was thinking on this.
I don't know what the replacement "life" criteria is, but folks using their computers harder than me(i.e. slogging through trying to do other things while Lightroom runs in the background, especially if they have a true base spec system) I could see eating 5% a month. That conceivably gets them to SSD failure within the extended warranty period(Applecare is 3 years).
BTW, I can't run it side by side since I sold it while it still had some value, but up until getting this system my "travel" computer was a 13" 2015 MBP-the last one with Magsafe, USB-A ports, etc. It had 8gb and a dual core CPU-it wasn't until recently that you could even get a quad on a 13" model. It had a blade-type PCIe SSD which Apple didn't officially consider user replaceable, but doing so was common on those models. For a while, you needed an AHCI drive for reliable operation, which pretty much meant using the awful and expensive Newertech ones(and yes, they really truly are awful) or finding a good Apple pull if you wanted to upgrade storage. I upgraded to a 512gb Apple drive, and then later on, when there was a firmware update that supported NVMe booting, put a 1tb Samsung EVO NVMe drive in it that double the read/write speeds of the old AHCI drive.
With all of that rambling, though, the point I'm making is that with the same RAM and storage specs-specfically 8gb/512gb-but also slower in general, fewer CPU cores, and not as tight of integration of the whole package, I didn't notice the swap getting hammered or the system-wide slowdown with Lightroom that I'm seeing on the M1. Yes, it would be "lazy" waking from sleep if I was doing a lot, but otherwise I wouldn't really have one program bogging it.
As an even more extreme case that I'm again pointing out, my MBP 9,1 has a quad i7 that's several generations old now(Ivy Bridge? The "bridge" that added USB 3.0), 16gb DDR SO-DIMMs, and a SATA SSD. It wasn't as snappy feeling overall, but Lightroom didn't seem to phase it.
I know I keep harping on Lightroom, but it's an important program to me, and conceivably a not insignificant portion of people opting for the "MacBook Pro" as opposed to the Air might want to run it. Lightroom isn't an every day, everyone uses it program, but it's also not some obscure "who's ever heard of that" piece of software. It's also been M1 native for a couple of months now(given Adobe's general track record, I'd not be surprised if it was one of the first 3rd party programs to go there, although they did drag their feet on Photoshop), so there's no issue of emulation overhead.