Many are wondering if the line will continue and we know for a fact that it will. Hasbro did confirm that later this year, this line will have toys representing elements from the 2018 Bumblebee movie. This line is very much like Star Wars Black Series in the way that while it will feature characters from across the movie franchise, it will be in this line that the more collector oriented toys for the 2018 movie will be released.
As a matter of fact, the Studio Series line itself, right now, is labeled as the Movie 6 toyline (as can be seen below). So it is meant to be on shelves the same year the movie comes out, though not necessarily having only characters from the film. This is all just to say that there will be more toys in this line past wave 2.
Now, about those toys, we know that an Ironhide is coming, along with a tattooed redeco of wave 1 Starscream (that hopefully comes with that saw weapon we keep seeing). We have a listing for this Starscream and a description which you can read below.
Starscream figure with Transformers: Revenge of the Fallen Cybertronian glyph tattoo deco
Premium figure and packaging inspired by the iconic Forest Fight scene
Figure scale reflects the character’s size in the world of Transformers: Revenge of the Fallen
Converts between robot and F-22 Raptor modes in 26 steps. Removable backdrop displays Starscream figure in Forest Fight scene.
Includes Transformers Studio Series 21 Voyager Class Movie 2 Starscream figure, detailed weapon accessory, removable backdrop, and instructions. Ages 8 and up.
Reach past the big screen and build the ultimate Transformers collection with Studio Series figures, inspired by iconic movie scenes and designed with specs and details to reflect the Transformers movie universe. In the Forest Fight from Transformers: Revenge of the Fallen, Starscream weaves through the trees in pursuit of Sam Witwicky and the Cybertronian secrets locked inside his mind. Racing toward his prey, he's pulled into a brutal battle against Optimus Prime. This Studio Series 21 Voyager Class Movie 2 Starscream figure converts from robot to F-22 Raptor mode in 26 steps and comes with a detailed weapon accessory. Remove backdrop to showcase Starscream in the Forest Fight scene. Lockheed Martin F-22 Raptor, associated emblems and logos, and body designs of vehicles are either registered trademarks or trademarks of Lockheed Martin Corporation in the USA and/or other jurisdictions, used under license by DreamWorks, LLC. Transformers and all related characters are trademarks of Hasbro.
We also know of a different voyager Optimus Prime toy coming and a voyager Bonecrusher toy.
Lastly, while there are other placeholder listings with code names for other classes, the one that has our attention is a listing with the title of "Transformers Studio Series Deluxe Ksi Sentry". Unlike other code names (like Stryker for Bumblebee), KSI does reffer to bots from the live action films. It is all speculation at this point, but we wished to point it out.
Also I'm probably gonna need more shelves. I love the backdrops so much but they do require a tad more space rather than smooshing as many figures as I can into tight spaces but I should be displaying them all neatly anyways and yeah..shelves... need more. The backdrops make it like the figures are halfway displayed boxed but open at the same time. Neat but easily accessible to pick the figure out and play with it. 
