That by no means confirms such a film will be made, but it's a good first step and perhaps a sign of Paramount's intent: That they are keen to secure the option to continue the series beyond the three films the main cast initially signed up for when production on the first nuTrek film began in 2007.
According to The Hollywood Reporter, the renegotiated contracts came about because it had been so long since they first signed up, so the original agreements had technically lapsed. In exchange for securing their place in a further sequel Paramount has agreed to pay increases, that will see Chris Pine's earnings for the new film at around six-million dollars, reflecting his increased star status, compared to his newbie pay of six-hundred-thousand for the first film, and four times more than the one-and-a-half million he got for Into Darkness.
The pay increases for all the main cast are though to have added between ten and fifteen million to the budget of Star Trek Beyond. It has not been revealed if the other main cast, including other rising stars such as Zoe Saldana, have also been secured for the next sequel.
To keep track of all the latest information on Star Trek Beyond, check out my Star Trek Beyond guide page.