In the official Discord, Devs are trying to silence any criticism made by people unhappy with the DLC being paid, which is a completely valid reason to be unhappy seeing how the devs said post-launch content wouldn't be paid.
Another thing to note, only 3 missions and 4-5 enemies is not worth more than 10 dollars here. The base game is 40 dollars and it includes 12 missions and 20ish enemies. I'm frankly disappointed that the devs failed to follow their own promises and are actively trying to silence criticism.