For free reimplementations of proprietary games, which can also use the proprietary data from the game it reimplements, should we add a freedom warning dissuading people from doing so?

It also seems the decision has been made to keep such engines around even if there currently exists no libre data to use with them. I agree, since people should be free to use whichever data they want with it, and might use the engine to reimplement proprietary data and then release it libre.

#1014, #1881, #2377, #3143, #3139, #3210, #3213, #3214, #3215, #3217, #3218, #3232, #3233, #3235, #3236, #3243, #3244, #3245, #3246, #3247.