Hidden Changes Discovered in Modern Warfare Season 3 Update

Call of Duty: Modern Warfare players have discovered several changes included in the Modern Warfare Season 3 update, released April 8, that did not appear in the patch notes.
Call of Duty YouTuber TheXclusiveAce tested many of the reported changes, managing to confirm some and leaving others inconclusive.
The High Alert perk now shows the direction from which the enemy player is looking at the perk holder by flashing a light on the corresponding edge of the screen. Two large doors have been opened to a passageway in the middle of Season 2 map Khandor Hideout.
A "clear new" option was added to the game, allowing players to clear any indicators that showed items as not having been inspected. Clicking L3 in the menus will remove all the green dot indicators at once.
Unconfirmed changes include nerfs for the M4A1 and MP7 in Warzone and a buff to the FMJ perk.
Modern Warfare Season 3 is expected to end June 1, though Infinity Ward has yet to release an official end date..