I don't get why people get upset over characters entering the battlefield now and want them just for mk10.. f.e. storywise, lots want Shinnok kept away because he plays a major role as it seems in the next game. I don't even care for this character and wouldn't buy him in a million years , but I don't get how his appearance now to please his fans would ruin his presence in the next game. story mode's over, what we saw is what we saw and ends there, DLC chars are basically irrelevant and bonuses for us.
now, the downsides are two for me.
a) idk what will happen to mk10. the game will probably remain awesome in terms of looks, maybe each character will slightly change or get from the start more brand new costumes that we got in mk9 and then even more new ones for mk 10's DLC. the fighting engine is great. cool, yeah. the roster worries me though

boon said due to this being a kind of reboot, there's a whole new timeline now. on the other hand, I wouldn't welcome in mk10 a character like Bo Rai Cho as they had him before. he's basically a joke but the 5-year-old kind of joke. idk about you guys but I don't laugh with a disorientated fighter that has beer moves or something. Bo Rai Cho would be great if he wasn't THAT fat and inspired a sense of wisdom like Gouken from SF. a true master for Kung Lao/Liu Kang, not a person you see and would assume irl he's a drunkard homeless person or something. if I knew that the roster would be solid and the generic fighters they made (there are LOTS unfortunately) didn't return or at least make them a bonus in the krypt or something, it would be great. just don't give me a Mokap guy in my freaking roster select screen.
b) DLC for mk9 right now is either lacking things I imagined or is unprepared for it. lots said the krypt is too small and they finished the challenge tower somewhat fast. boon said once that their starting plan was 1k challenges I think. if that were the case I doubt anyone would even consider challenge tower missions as DLC

but now, lots do and want that. xray moves seem to be out of the team's plans. fatalities are still discussed and negotiated, they are not sure yet. offline bosses are probably out of the table for now. story mode is DEFINITELY out of the table. stages are most likely out of the table. I mean come on. stages too? and fatalities? I'd want at least those two. the only thing that's sure atm is characters and costumes and we obviously don't know their plans after the release of ???.
in conclusion, my vote goes for DLC but that's only due to wishful thinking. I WANT this game supported. but the truth is, with just costumes and characters, the DLC will probably not last as they would want it to last. they should get creative and add more things in their DLC plans. costumes, xrays, fatalities, more special moves, more test luck modes, those are easy. maybe more stuff in the krypt? that would be good too. stages would take more work but who wouldn't welcome The Pit 3? or The Bank? or Motaro's lair? there are TONS of stuff they can either work on 'briefly' or harder things that can be added in their programme, I hope they do that