After Call of Duty: Modern Warfare Remastered, Activision indicated they were hoping to follow suit with other Call of Duty remasters, but they haven't said much about that plan since then. A ratings board leak coming out of Europe, however, suggests that the follow up to that plan may be coming in the obvious form of Modern Warfare 2.
No such remaster has been officially announced by Activision yet, but a listing (and subsequent 18+ rating) for the game has appeared on the Pan European Game Information board, or PEGI. It doesn't give any details, but if PEGI is saying it, it's very likely not made up out of thin air.
Modern Warfare Remastered was included with special editions of Infinite Warfare, the last Infinity Ward game in the series. Seeing as how Infinity Ward's Call of Duty game is presumably up to bat this year, Modern Warfare 2 Remastered makes plenty of sense again. It will be interesting to see whether the game will be available separately from the start or will follow in the same footsteps as Modern Warfare Remastered and only be available on its own later.