playerOnline Argument In Identifier (@a[]) Commands

As of version 1.21, when running /tag @a remove exampleTag, it will only apply to all players that are online, just as /scoreboard players @a[tag=exampleTag]... will only affect online players. If a player is offline, the tag will not be removed. Right now, there is no way to run commands on players that are offline(not including specifying a single player or getting into very complicated macros). My suggestion is to add an argument in the identifier part of a command (@a[tag=exampleTag,team=exampleTeam], etc.). The argument would be named playerOnline, and would function as follows:

- @a[playerOnline:1b] applies only to players that are online

- @a[playerOnline:0b] applies only to players that are not online

The identifier defaults to 1b when not called for in a command, and would only apply to players (Ex: this would not apply to pigs).

This would solve problems in mapmaking, where creators would want to remove a player's scores from a server when they log out, and would also serve as a powerful way to access player data at any time.