ZOMBIES mode was removed due to it not reaching the high quality level that we desire for all modes in Call of Duty: Mobile. However, we may improve it and bring it back at a later date, at which time your progress, revive coins, and shards will also return.
All gear acquired in ZOMBIES mode, whether it is characters or weapons, is usable in Multiplayer and it may come to Battle Royale in future updates. However, ZOMBIES mode specific traits on weapons will not carry over to other modes.