Everything gets updated eventually. They have a good track record with keeping old content relevant in this game.

A while ago the plan was to offer large scale exploratory mission updates in every other major patch, which would mean something big added for patch 3.3 just like Diadem was added alongside Void Ark in 3.1, but they haven't talked about it in a long time so I wonder if the plan is still the same.

Will be interesting to see what happens in the patch 3.3 special Live Letter from the Producer.
And I agree on the need for larger amounts and methods of obtaining brass/steel spoil tokens, as this is the unique reward that exploratory missions offer and needs to be boosted. In particular a much larger yield of steel tokens for gathering classes will help with obtaining materia for craft/gather.