I'm not knowledgeable about OSRS gold but I'd suppose that all sold bonds work sorta like gift cards, which I vaguely remember how to account for lol. All marketed bonds are prolly put to a deferred revenue account until they can be matched with them being redeemed, all of the while aging the payable amount that is the redemption cost.
You will notice that if they contribute a few to each match (43M RS3, 65M OSRS), which adds up to 108M, but the actual revenue throughout 2019 was 110.8M. Maybe part or all of that unaccounted for 2.8M is unredeemed bonds.(https://www.rsgoldfast.com/News/osrs-freeing-sir-amik-varze-guide.html)
You're not adding other income, merchandise at 2.6m and advertising revenue at 225k. Add them to the RS3 OSRS amounts and it is logical.
It's quite interesting that the huge boom in buy runescape mobile gold inhabitants did little to halt the decline of MTX revenue; I am inclined to believe that 2019 was way, far worse for RS3's MTX compared to stats (and the document) say .OSRS is obviously doing gangbusters. No surprise there, the game's been doing incredibly well and everyone knows it.
I'd recommend getting wary, though; I remember a couple of months ago that there were rumors the bigwigs were beginning to seem to OSRS as the long run as a result of financials, and this kind of information would actually encourage that talk.