I think Bethesda Game Studios has plenty to fund that already. To be honest with the profits they got in the last 5 years they can probably fund 10 full games just from that.
Smaller studios do use the money they got from selling the previous game to fund the next, but Bethesda has a profit of hundreds of million dollars while still being a small studio (around 150 people).
Then we have Bethesda Softworks that is the distributor, which also makes tons of money, then we have Zenimax that is the "sugar daddy/master" of both (and other studios too) which can always inject millions of dollars in a game if they know they will get a profit (and TES games always make a profit). They don't need the money of Wolfenstein to finance a TES game.
Oh I know, but every dollar helps.
I can't stand modern AAA development.
I wasn't always like this, I used to buy CoD every year, Battlefield 3, I would have bought Halo if I had an Xbox.
I wasn't much of a PC player really, grew up on PS2 and Nintendo DS/Wii.
I think Dwarf Fortress fucked me up for good, such amazing mechanics which all (mooooooooostly...) work perfectly and logically, then I started getting into 90's games...Which are superior mechanically to games of today.
Doom 1? Colourful and unique enemies which all work perfectly, no scripted bullshit. Goood map design, no need for gimmicks like jetpacks and such. Awesome weapons which feel powerful, even the lowly shotgun can 1 hit enemies from far away, yet alone the SUPER shotgun. Enemy count upwards of the thousands on some stupid WAD's.
Not-Doom 2016? Drab unoriginal enemies which need scripts for bossfights, boring map designs, need gimmicks to make it work, ruined weapon balance, unlimited ammo for grenades and pistol and shit, and enemy count is capped to 12.
TWELVE.
WHY SHOULD I HAVE DOOM 4 IF DOOM 2 HAS LEVELS UPWARDS OF FORTY AT ONE TIME!?