I think this is an absolutely wonderful idea, something I've been wanting to start myself for quite a while (not this exactly, but something that would get pokemon unbanned) but I have the leadership skills of a wet paper towel, so that wasn't going to happen. I'm in, I'll go by [MAT] Bladeezz on PO, so feel free to challenge me.
The only problem I see with this project set up (which could actually be a really huge problem) is that every team is going to be using this periods pokemon, which imho doesn't really give any relevant results to OU. If every team is using Garchomp, versus others participating who will also be using Garchomp, it's not really testing how the pokemon would do in OU (only sort of), but only in this MAT tier we've made between ourselves. I don't really know how to solve this problem, only thing I can do is hope to inspire someone to come up with one by saying we should look at how the OU DW tier is playing out right now (a place where manaphy, garchomp and friends are all usable, except this kind of defeats the purpose of testing things like just Garchomp without Excadrill). Really hope this project works out and can get some diversity back into OU (god would I love to use my favorite dragon in OU again, I miss him.)