There will always be characters you won't play as in WWE games.
Everyone has their own handful of favourites to pick and play as, but that doesn't stop the community from buzzing about exactly who will be included on the roster every year. Will 2K cram as many on-disc as they can? Are they going to hold back some top names for post-release DLC? Which Legends will make it on there and who will miss out? Those are the sort of questions doing the rounds at the moment.
This articles predicts every single superstar, including Legends, DLC, Cruiserweights, NXT and tag-teams, who should be in WWE 2K19. It's unlikely all 152 of the acts chosen will be available out of the box (gotta' get those precious post-release dollars, after all), though most of them should be; 2K seem to love pushing up the numbers and claiming each subsequent game has the biggest on-disc roster ever.
Another thing to note is that, due to the size of the list, there isn't necessarily a scale from 'least important' to 'most important'. All stars are categorised to make it easier to browse, and the emphasis is more on who will actually be included rather than who's been on fan wish lists for the past few months.