I read up a bunch on the Shantae issues. Some people that regularly open GBA games posted they had seen similar in retail games. Obviously not completely because they have to use that one custom (fpga?) chip for the custom gba bus and this is a new board... but like, the chip condition isn't that unusual. It's not something I care about one way or the other as I'm not buying modern releases of games for old systems weather it's old unfinished games that are now finished for the first time and put on repro carts or full on custom roms or existing games you can still get on the aftermarket. Like, not for me. But I can see why some are miffed that bought this and opened up the cart to see it wasn't as clean as expected. But it doesn't seem to be everyone. Definitely check yours out if you bought it.
The deal with the wrong game showing in emulators is not due to reuse of any chips or boards, it's because they reused a known cart ID. So the emulators know that id goes with a specific game. Why did they do this? I don't know unless the ID has some identifying info that the gba uses and this was to ensure compatibility. But whatever the case, this a hack of a rom or reused boards. Yes, they used some refurbished chips, but many of the chips for old games aren't manufactured any more nor is there still old new stock floating around. Not sure if GBA is one of the platforms, but it wouldn't surprise me if it was.
Again, not that I bought this. So no skin in the game either way. I get the FOMO of this... especially with the resell value of old Shantae games and this being previously unreleased. BUT, like, this is LRG.