I would love to see Megan again in Transformers, and Shia also. They are both great actors, i remember when the first transformers came out, my parents rented it and i didn't want to watch it because its a boy movie, but i loved it. I still love it and the actors/actresses. And even if Megan is in TMNT2 that would be awesome but doesn't mean she shouldn't slowly come back to film Transformers also.
Just like Chris Pratt in 'Guardians of the Galaxy' and 'Jurassic World'. Megan and Shia can and should make a way back into Transformers. In the 3rd movie when Megan and Shia break up and he has another girl, I thought it was a little disappointing that she wasn't with him anymore, even though the other girl was great I still missed the Original girl Sam loved. Also in the 4th Transformers it was an amazing movie and i love Mark, but i still missed Shia, because i came to love and want to know more about Sam and Mikaela's adventures with the autobots.
The movie franchise can lets say have Sam and Mikaela get back together, they end up getting back together because of everything they lived though together, they will always love each other. And still have movies about other people to shake it up, like how the 4th one does it. Then the humans (Shia, Mark, Megan) meet somehow and work together to solve the problem at that time.
I hope others have an urge to see the same thing. Im excited to see how it develops and hope that we will be able to see the actors and actresses we all love, especially since Megan and the director made up.