Basically, after scanning my Monster Hunter Rise amiibo so I could add their data to my amiibo spreadsheet, I was surprised to find that there is a HUGE gap in amiibo ID numbers between Cat Peach (03A7; 935 in decimal) and Magnamalo (040F; 1039 in decimal)—103 unused IDs, to be exact! This gap in IDs is VERY interesting because there are absolutely implications with that...
See, if there were just a few unused IDs between there it wouldn't really tell us much. That happens fairly often and those few gaps are almost always filled in by soon-to-be-released amiibo—almost always, that is (more on that later). But there being 100+ unused IDs here is VERY important. Why? Because this is something that has been done multiple times before—for amiibo card series. Nintendo typically allocates batches of 100 IDs for each card series. The Animal Crossing amiibo cards Series 1–4 take up 400 IDs, 100 per series. Then the 5 promo cards come right after Series 4, but there are another 95 unused IDs after that—that's because Nintendo saved another batch of 100 IDs for these promo cards, even though they only used 5. The same is true for the Animal Crossing: New Leaf - Welcome amiibo series; 100 IDs were reserved for that, with half being used for the 50 cards in that series, plus the 6 Sanrio cards right after that, leaving 44 empty spots.
The Mario Sports Superstars cards are similar to the Animal Crossing cards, but that series saves 120 IDs instead of the usual 100, 90 of which are used while 30 remain unused. Nintendo probably saved an extra 20 IDs there in case they wanted to release a set of promo cards (maybe, like, one or two for each of the 18 characters), but they never did. The Shadow Mewtwo card and the Jikkyō Powerful Pro Baseball cards (and the Super Mario Cereal amiibo, since that's technically classified as a card too, lol) aren't really whole series like the others so they don't follow this same trend of allocating batches of 100 or so IDs regardless of whether the series will actually use all of those IDs; instead there are no skipped IDs at all after each of those, as is the case with the vast majority of amiibo.
So what does all this mean? Well, a gap of 100+ IDs means we're almost certainly looking at a new series of amiibo cards here; it falls exactly in line with how the Animal Crossing cards have been handled before. With the Sanrio cards having just been brought back and Animal Crossing: New Horizons having been updated to add more functionality for them, plus the fact that we know post-launch updates for the game are set to continue despite the fact that we're past the one-year point and there are no more new holidays to add, the timing seems perfect for a new series of Animal Crossing amiibo cards for New Horizons (alongside an accompanying update for the game) to be imminent, consisting of new characters that don't already have amiibo cards like Flick, C.J., Raymond, Audie, etc., and maybe some new cards for characters with updated looks in New Horizons as well, like Tom Nook, Isabelle, and such. So, yeah, I think it's pretty safe to assume that 100 of those 103 IDs are for new Animal Crossing cards!! At the very least, it's a safe assumption that this is some kind of new amiibo card series, and I don't think there's really anything else that's more likely right now than a new series of Animal Crossing cards.
