They don't say a damned thing anytime your account gets nuked. Hell, when I tried buying a Nexus 4 it mysteriously never shipped and I only could get in touch with a robot support person. I said fuck it, cancelled the order, and went to a T-Mobile store. Never bothered to deal with them again.
In some jurisdictions it is illegal to let your client know they are being secretely investigated. Such statement may interfere with the investigation - they may destroy the evidence etc.
> "Google's policy seems to be radio silence in all cases"
This may be an intentional decision to cooperate with law enforcement. If they only go silent in the case of ongoing investigations, then "Google went silent" functions in the same way as "the warrant canary disappeared" does for other sites, which could in theory jeopardize an investigation.
