If a player dumps there items into a Meteor chest in the middle of nowhere and you come across it can you technically grab it?
Breaking or picking up any items that other players has put down that aren't associated with you is recognized as griefing. The rule says breaking another players belongings protected and unprotected is griefing. So don't pick up the items in the chest.
I think the important point here is that it was stated that it is a "meteor chest" not a chest that a player put down... I would suggest there is a special exception for pre-generated loot chests like meteor, mineshaft or dungeon, if a player comes across a naturally generated chest somewhere and dumps stuff they don't need into it in order to make room for the stuff it contains when they find it, then anything they leave behind should be fair game really as it is after-all still a loot chest, even if it does now contains different "loot" than when it was first generated.
I really don't know what a metor chest was, though I assume anything that players don't want was dumped in there for a reason, I see no problem why they cant take it.
I agree with you, you have a point there I often too just dump things I don't need in loot chests arround the world
Plus, with some loot chests, the player does not really know what originally was in them. I have found rotten flesh to diamond blocks and everything in between. The only was to know is if it is an item only available if a player makes it (and that is still hard to decipher, cause I have found dyed armour and such).