Last year, PlayStation made the controversial decision to announce it would be closing down its PS3, PSP, and PS Vita storefronts. A decision that turned out to be so controversial, the backlash towards it prompted PlayStation to make a u-turn and for now, those online stores will remain open. Cue Nintendo revealing the same news regarding the Wii U and 3DS stores this year, and despite some fresh backlash, there appears to be no going back in this instance.
The closure of both storefronts will be gradual, with some elements remaining open until March of next year. There's also evidence that despite the console itself being discontinued in September 2020, Nintendo has quietly been reprinting some of the 3DS's rarer games in the UK and Europe. Evidence pointing to that was spotted by pikuri and shared on Twitter.
One indicator that certain 3DS games appear to have been reprinted as recently as 2021 in Europe is a narrower case. 3DS games had a narrower case in Japan than they did in Europe. Some games that launched prior to the console being discontinued have since been spotted with the narrower case usually restricted for Japanese 3DS games. No confirmation from Nintendo that they have been reprinted, but seemingly evidence pointing to that.
The other clue, again highlighted by pikuri, is an otherwise unassuming bit of information included in the blurb on the back of the games. Since the UK has now officially parted ways with the EU, you can tell if a game sold in Britain was printed post-2020 by the UK economic operator information on the rear of the case. Again, nothing official from Nintendo, but another indicator that Nintendo has been reissuing some of the 3DS games that might be harder to come by, especially with its online store closing down.
There's still hope that Nintendo will make a similar u-turn to PlayStation between now and 2023 and the Wii U and 3DS stores will remain open beyond their planned shutdown dates. Nintendo is much more adept at digging its heels in when it comes to these sorts of things though, so it's unlikely. As for piecing together your physical 3DS collection, reprints might make that a little easier and slightly ease the rapidly rising prices of games on resale sites.