Wait so even though it's right there in the Bible nobody is able to eat it because it hasn't been done in a long time? There are probably good reasons why it was included as an allowed food (nutritional or symbolic). Is there any teaching that in the future lost traditions like that might come back?
I think Wetas are more like a cricket than a grasshopper anyway though.
One reason locust is kosher is in case they destroy large amounts of crops people must eat them or they starve.
I don't know if there is a teaching that lost traditions would be reinstated.
Yemenite Jews and Some north African Jews still ate these things until the 1950s and few even to this day. But most communities stopped eating grasshoppers hundreds of years ago.
There are other animals that are technically kosher but are not eaten, like the Giraffe. But it is not kosher because there is no tradition nor knowledge as to how it should be slaughtered. But grass hoppers don't need to be slaughtered so that reason doesn't apply to their case.
Grasshopper is obviously a very abnormal item on the kosher menu and the risk of eating a non kosher insect must have been the reason why eventually most rabbis forbade eating it altogether.