if a post is posted in a community that does not make part of the Incubation Program of OCD, does it have anyway the chance of getting curated by OCD?

Yes, it does. OCD curators are curating across the chain, not only the incubated communities.

That chart is from January, but even if it was new, you should not chase a community just because you see it is the most voted.

My humble advice, write about what you like, post about things you find interesting, engage with like minded people and you'll see the results.