It makes sense because many gamers would love to witness this trilogy on Xbox One and PS4 if it came out in the form of a full remake. Moreover, it would be three games available for the price of one.
We would also get World War II content if Activision decides to older COD games by Infinity Ward. Now infinite could also refer to Space since Space is never-ending and limitless, almost like infinity. There is a pretty long segment in Ghosts, which actually takes place in space. Therefore, Infinity Warfare could be a sequel to Ghosts.
Moreover, games like Call of Duty are getting more futuristic year after year. A Time Travel theory is also available. Activision simply tries to develop a COD game that trumps its exact predecessor. Time Travel would make it bigger and highly bombastic. It would give us an interesting story campaign along with great multiplayer dynamics.
The word infinite could also mean a combination of various game modes. It could be almost like Destiny meets Call of Duty. Whatever Activision has planned for us, they better know that Battlefield 1 looks incredibly promising. In fact, some COD fanboys might have already changed sides, you never know.
Stay tuned for more updates on Call of Duty: Infinite Warfare!