There is an opinion: MW3 weapons will take precedence over MW2 weapons
Call of Duty’s announcement that MW2 weapons will be carried over to Modern Warfare 3, allowing players to use them at launch, CoD expert WhosImmortal explained why they probably won’t be “as effective” in the game.
According to WhosImmortal , while players will retain access to all of their MW2 operators, weapons, and game progress, from a business standpoint, Activision will apparently prioritize Modern Warfare 3 weapons over MW2 weapons.
“I guess a lot of MW2 won’t be as effective in MW3 because then you won’t have a reason to buy MW3, level up new weapons, and buy new weapon packs,” he warned during his video. He then added, “The more effective the MW2 weapon, the less money you need to spend on the content listed in MW3”
One of the hardest aspects of leveling a weapon is having to use it without attachments at the start. Undoubtedly, this will give players the opportunity to start their first game using already familiar equipment, allowing them to enjoy the game from the very beginning.