They have only the aired Japanese episodes that lie ahead. Any info they would have on episodes not yet aired in Japan, if any, would be coming from the same sources as were getting them from ourselves. They're not collaborating with the Japanese storyboard directors or anything like that.
Think about it for a second. In order for an episode to be dubbed, the dubbers (TPCI) need the footage of the episode from the original source (Shopro). Barring two specials which are arguably non-canon to the main anime and specifically planned for the purpose of a US initial airing, Shopro has not given footage of any raw episode to international dubbers before the raw episode airs in japan, and for good reason. What if something comes up that forces them to remove an episode from syndication, or make a major edit to avoid a lawsuit? These things only come up days before the episode's intended air date at the earliest. It wouldn't make any sense for any localization company to waste time and effort on an anime episode that may need to be scrapped due to a last minute major change to that episode by the original producers.
All TPCI does is localize the Japanese pokemon products for international audiences. Not only does this not require them to have foresight from future events that occur 25-30 episode later, we've also seen plot point mistranslations (Dawn's nickname for example) that could have actually been avoided with such foresight.
As for the season titles, that's just TPCI's own interpretation of what future events will be based on the episodes that have already aired in Japan for that season. Since the new season in the states usually starts with roughly half of its episodes already aired in japan, it really isn't that hard to put 2 and 2 together to figure out the general plot of the remaining episodes.
That said, the possibility of doing something in Kanto/Johto/Hoenn/Sinnoh/Orre, though slim, still exists.
