Is that direct or newsstand? It definitely has the same interior and back-cover ads as the August '90 DC issues, which in my experience would've gone on sale in April. (That's why the letters at the back of a given comic were typically about the issue from 4 months before.) But I checked the GCD for the corresponding monthly issue, TNG #11, and it gives a July 12 date for the direct edition and no specific date for the newsstand edition.
The back cover ad for that month's issues was for a movie that came out on July 20 (Navy SEALs with Charlie Sheen). I'm not sure whether that argues in favor of a July release or against it (depending on how far in advance they prefer to advertise movies).
Well, in any case, the important part is that the issue was written well before Robert Picard was introduced on the show. (Or Robert Picardo, for that matter...)