Has there been any indication given in the XY coding about the new forms of Kyogre and Groudon, either Mega or alternate? It is clearly stated that they are "new" pokemon from multiple official sources, so surely, if they were going to put everything that they have in store for Generation VI in the coding for X and Y, then Kyogre and Groudon would be included as well.
I don't buy the argument that GF can't implement new Mega Pokemon or abilities this generation just because they aren't coded into X and Y. Off the top of my head, the hidden data in the coding include Diancie, Hoopa, Volcanion, Mega Latios and Latias, the Eternal Floette, the extra Vivillon design, Thousand Arrows and Thousand Waves, and some random Splash-esque move. Of those, Diancie and the Pokeball Design Vivillon have been announced and will be released prior to November.
We can make an educated guess about the Thousand moves, but even if we do, it doesn't really matter because we don't know what they're for, and we certainly don't know what their impact on the games is fully meant to be; they are still shrouded in secrecy, so it doesn't really matter that they are included in the coding. This would leave Hoopa, Volcanion, Lati@site, and the Floette, with at least one of these being likely to be released prior to November, the most likely case being so that it can coincide with the release of ORAS, and yet still be freely compatible with X and Y.
This leaves three options for GF already coded in for them to use at any time; three back-ups, if you will. This allows them some flexibility, rather than to forcing themselves to rely on a rigid schedule. For example, what if the announcement and subsequent release of ORAS had to be put off by a year. With the Vivillon's release going through June (although, to be honest, this is new, but even so, Vivillon's pattern is more of a gimmick than something important) and Diance's release going through August and September, they are setting themselves up to be locked into a release schedule that all but runs up to November. If, for whatever reason, they could not meet that deadline this year, they would be out of "OMG New Pokemonz!!1!" events that they could use without using the one that would be planned for the release of ORAS. By including back-ups, they save themselves from putting themselves in this kind of situation, and the embarrassment of saying "Here is a totally new Pokemon, but because we didn't plan ahead, here's a spiffy new patch to go along with it!". It would not be smart business for them to not have a Plan B, and a Plan C, and so on. Additionally, with the exclusion of the the Thousand moves, everything on that list will likely be an event in the first place. By having them pre-coded, they are saved from needing to release a mandatory patch with each new event as opposed to say, alongside each new game set.
Remember, GF worked very hard to prevent X and Y from being hacked in the first place. That being said, what better way to prevent information that won't have to potential to be distributed via some future event from being found when the game is eventually hacked, than to not have that information available to be found at all? Two patches have been released for X and Y already, and the concept of a patch for a pioneer game that is implemented by successive games has already been used in the past. The smart thing for GF to do, if they want to introduce more Megas or formes, would be to release a standard patch, and then include said patch in ORAS, so that if someone tried to connect X or Y to OR or AS, but they had not yet uploaded the patch, they would have the option to do so then, otherwise, be unable to connect at all. This isn't like Generation IV or Generation V, where the technology was more limited. There is already precedence of GF freely providing the patches needed to fix and upgrade the games coding as they please, something that hasn't been seen in the past unless it was absolutely needed, and it would not be surprising in the slightest to see them take full advantage of this capability if they want to keep certain information hidden from an otherwise nosey community.
As for arguments against more Generation VI Mega Evolutions, I can't claim to know what GF is thinking or planning, and it could be that we only get the thirty Mega Evolutions that are already known, and Kyogre and Groudon just inexplicably get new alternate forms just because GF can. But think of it like this: Generation VI is defined by two key concepts, the Fairy-type, and Mega Evolution. Just by this fact alone, and knowing that Kyogre and Groudon are getting new forms, which scenario is more likely? They randomly get brand new alternate forms twelve years following their initial release, or, they get new Mega Evolutions to coincide with an advent that the current generation is partially defined by? It doesn't seem to be that hard to figure out. Following this line of reasoning, if they can do it for Kyogre and Groudon, where not even two weeks ago, the community didn't have a clue to suspect them, why can't it happen for anything else? In my eyes, Sceptilite and Swampertite are very much a possibility, if only because Blazikenite is already a thing.
Game Freak now has the capability to completely hide elements that they want to remain hidden, and not have to worry about all of their secrets being found out, while keeping the gameplay consistent. I fully expect them to use it.
