They allready nerfed the AP gain from these in AP level. It is just the exp boost from these Blizzard are killing = eternal farm from Paragon rewards which is awfull to grind allready. So they are kliing the interest in going to Mechagon by doing this.
I hope they change it back (like 8.3.5, as mentioned above) so you can earn that juicy paragon rep in the future.
From a pure short term and even long term gold perspective this will not matter. Without any rep buffs and not counting other reagents, 100 spare crates = 20 Microbot xD pets or 33 Utility Mechanoclaw pets. Other than the paragon techniques and toy, the paragon reward of 5k gold is no where near the value of the reagent.
Have you also checked the rep items you can earn or buy from the Island Expedition vendor? They're 250 rep each and can be stockpiled. I guess farming Dubloons is a lot slower.
Revert Rustbolt Resistance Insignia, revolution of our time!
I think this is alright as long as I end up getting the second rank 4 essence I'm missing from Rustbolt after 22 boxes. If I still don't have it by 8.3, then this nerf is going to bother me quite a bit.
...and to stop the WF guilds from killing themselves, they nerf the farmability of that damn paragon blueprint and the legendary azerite appearances. Lovely.