Losing Gliscor as a potential option is pretty huge as well.
Maybe I missed this - but why Smoochum of all things to be what appears to be, the only non-Plat dex mon available before post game in this game? Just seems incredibly random to me.
Oh, Smoochum is actually a pretty cool one! I have an answer to this!
In the original DP, most of the Pokémon you needed the National Dex to find were either only found in the Battle Zone (i.e. not mainland Sinnoh) or locked behind some special encounter method like swarms, the Radar, dual slot mode and so on.
Smoochum and Jynx were actually the
literal only exception - they were still found in a postgame-only
area (and one you needed the National Dex to reach, so they couldn't make it count for the regional dex before then), but that area was
Snowpoint Temple, as much a part of mainland Sinnoh as any other Sinnoh-dex Pokémon!
In some ways, it was about as close as you could get to "actually Sinnoh-native all along" - it was a very unique position for only the one line, so maybe they were making a subtle shoutout to that distinction by making it an honorary member of the Sinnoh dex!
As for Pinsir, Scyther and Pinsir were version-exclusives in DP, but they were broken up a bit in Platinum (where Scyther was added to the regional dex and Pinsir was not). Since the devs seem to have wanted to keep above-ground encounters the same, this making them exclusives in BDSP too - so if Scyther "had" to be added to the Grand Underground because it was in the Platinum dex, they still wanted to preserve its version-exclusivity, so they added back its old Pearl-exclusive counterpart Pinsir to match!
Teddiursa is... uh... honestly the most random of them - they also added it to Legends for no obvious reason
(and it's one of only three lines like that so far, the others being Vulpix and Spheal) and we've even seen an Alpha Ursaring, so maybe they just felt like it should have been in Sinnoh all along? :'D
Out of the loop here; what's the USUM Numel situation? All I can see on Bulbapedia is that it wasn't available in SMUSUM
Basically, every Pokémon that had a Mega Evolution could be caught natively in USUM
(most were specifically added to the regional dex, but there are also Island Scan encounters and Ultra Warp Ride encounters for the few that weren't, Legendaries obviously included in the latter).
A lot of people took this as a deliberate choice, probably meant to coincide with the fact that every Mega Stone could now be bought at the Battle Tree and not just the ones in the regional dex.
The only exceptions were Diancie, which cannot be caught natively in any game, and... Camerupt, for no obvious reason at all - people were wondering how to get Camerupt for a while because it seemed so bizarre for it to be the only one, and there were so many different encounter methods that could easily have accommodated for it, but for whatever reason, it was forgotten. :')
ALSO A QUICK THING ON THE SHEET
I am deeply sorry-- I misinterpreted a somewhat important bit of data and have corrected it since my last post!
What I had listed as "special moves" the first time around were actually
the moves that were specifically prevented - in other words, I had them completely backwards! OTL
A Pokémon in the Grand Underground can potentially spawn with
any of its Egg moves except the ones that were specifically enumerated in the files. I have corrected this and added all of the legal Egg moves to the sheet instead (while keeping the Forbidden Egg Moves tab intact because it's cool information)! Just noting this because I know a lot of people looked earlier and would have been misinformed >->
in conjunction with the above post: RIP Chatot oh my heck - it was so close to having Boomburst after all
