It does mean a lot of prospective PvP obfuscation tactics might be nil.
Hmm, unless we make this a function of espionage teams, perchance? Make it so espionage can yield "fleet weapon usage by total tonnage" or "platform force value" without specifics? So for instance, an AI could use espionage on you or interrogate your crew (or vice versa) to become aware that you have a lot of sensors with high tracking speed multiplier/turrets with a specific tonnage gear without actually mentioning it's respective tracking speed, or that a fleet is mounting 200HS worth of reduced-size launchers, or so forth. It'll allow AI's and the player access to the more transcendental knowledge, perhaps AI moreso when you've cranked their difficulty, (hopefully) giving them access to more military academies.
Actually it would make more sense IMHO if this was not tied only to espionage teams, but instead to a general type of "knowledge of enemy ships" which is gained mainly from salvaging their warships.
Salvaging many warships of an empire should give you a pretty good idea about the general makeup of their ships. Things like their performance, techlevel and weapon percentage all included.
I do agree that interrogating crew could boost it, and it could also be boosted massively if you manage to capture ships ( making this more worthwhile except for RP purposes ).
Overall I feel this part of the game is a bit lacking. If I have destroyed half their navy, captured all their surviving crew and salvaged all their ships I should have an almost complete picture of what I am up against, and I should also know that I have destroyed roughly half of their navy by now and rough estimates on their ship building or the capacity of their yards.
Historically for example during WW2 the allies were able to estimate German tank production within a few percent accuracy by such a simple thing as counting serial numbers of parts in the tanks they were knocking out and salvaging in Normandy.
This could neatly also solve the problem of giving the AI enough knowledge without cheating, by just making sure they aggressively salvage stuff and capture surviving crew.