Nothing has been said, but logic would lead us to believe that the shields will come in 2.1, given the current end-game gearsets. Likely part of a reward for Primal EX fights or Treasure hunting (as these are the only conceivable content which would drop ilvl90 loot).

Edit: Personally I doubt treasure hunting will yield ilvl90s, as from what we've seen the content is done in small parties (4-man in the trailer).