12900k is still clocked higher and has more L3 cache so it should be faster in gaming. Games don’t care about core counts so 12700k has that covered.
But that's my point though! The 12900 will be faster for games yeah for sure, but will it be that much faster to warrant the extra cost? Not so sure, hence why there must be a reason why Intel left it out of their slides knowing that if it was in there, most sales would go to that instead and also why there's this whole embargo going on because reviewers will no doubt mention the 12700K even though press kits don't include it.