Maria's battlepack theory is based on many years of collecting work, I think it deserves all the respect.
https://www.reddit.com/r/battlefield_one/comments/17eldms/comment/k66xz19/
Maria's explanation on BF1 subreddit:
How do I know? Because of these three factors:
It was one of those battlefest/holiday exclusive skins that were introduced for participating in certain events.
And this is literally the game telling you what's included - On the right-hand side of the battlepack there are listed skins. So take for example the regular battlepack (which is also the EOR BP), given that it contains the largest pool of skins in the game. So, take for example its column - it has 15 listed (potential) skins, and +750 other (possible) skins. And the wording is really important, but a lot tend to miss what the game is literally telling them, Dice (for the most part) did a very good job with the wording, and this is coming from a person who had graduated law. The skins on that list do not indicate that the drop is limited to one of those 15 showcased skins in particular, those are just potential drops.
There used to be a time where each battlepack had a Revision, and it listed just a particular set of skins and the drop was limited to the ones listed, that is not the case anymore, this is why you see the label "Ultimate Revision" now on each of the three store-bought types of battlepacks. Because it can't show all of the 765 skins from the pool and unnecessarily bloat the game's pagefile, hence you see just 15 example skins. Back in the day you had, say, the "Winter Revision" and you had just a few handpicked skins which were, for the most, part white (to match the theme).
Why am I telling you all of this? Because over the years I kept track of each and every skin shown on that list and came to the conclusion that from all of the 846 skins, 81 skins were never included on there, now if you do the math and deduct the skins from the largest pool (765) you get the exact same number of 81 (and 79 in the Superior one since two of the M1911 skins which do not drop from battlepacks are of Distinguished rarity, so naturally you won't see them in a legendary-only BP). Skins that never showed up on there were for example No. 3's Holiday Package, the PTFO skins, the Road to BFV skins, etc (just to name a few). However, skins like the M1911's "Care Package" do appear on there, and it's part of the drop pool. Now the "Super Rare" label is what's the most confusing part, because that phrase gives out the notion that the item might drop from battlepacks, it's just that... it's super rare, in reality - this label is based on the pricing. All of the Super Rare skin are priced at 10k scraps. Now, if it's a case of Occam's Razor or genuine malice on EA's part to use that phrase I cannot tell.
3. This adds cumulatively with what's been said in the previous paragraph. I've opened about 32,000 battlepacks at this point, and I've never stumbled this skin, albeit I've had the "Care Package" drop, and two Super Rare vehicle skins. I even kept track and created a database in which I've named and documented each drop, but I do not know where I can upload it since the file size is really big, but just to give you a quick preview - https://i.imgur.com/ReMElnl.png
NOTE: The whole documentation inside the screenshot is referential, just because certain skins have been recorded to drop doesn't necessarily mean, on its own, that those that didn't drop do not drop. I wanted to test if ANY of the pinpointed 81 skins from the whole documentation cycle would actually manage drop, but not a single skin from the non-previewed on the right-hand side of the battlepack pool page actually dropped, further confirming that these battlepacks have a pool of only 765 from the total of 846 available to the players (non-developer) skins - just as advertised on the right-hand side of the battlepack. And these skins don't have special drop rates, they are regarded as non-super-rare "Legendary" skins (with the only exception being the No 3 skin, and two distinguished M1911 skins), so normally if they were part of the drop pool their drop chance would've been similar to any other non-super-rare "Legendary" labelled skin.
The pool for the Superior Battlepack: 118 (+15)
The pool for the Enhanced Battlepack: 378 (+15)
The pool for the Regular (End-of-Round) Battlepack: 750 (+15)
The total amount of skins in the game: 846 (only regarding scrappable, Inventory based skins)
The pool for each: https://i.imgur.com/MQXOxeg.png
And keep in mind, I've collected all of the skins in the game (it's on my profile if you are curious to see it). I'm friends with one Twitch streamer named Lagoass who'd also managed to collect everything and the battlefest/holiday introduced skins never dropped for him as well. Since I started the game quite late after its support had been halted and didn't get the chance to participate in these events, I've managed all of these 81 skins through the Exchange
