Has GTA VI been announced for PC?
No PC version or date has been announced.
Past Rockstar release patterns are not treated as evidence for GTA VI.
The evidence
No announcement found in the sources checked on the verification date.
Rockstar Games SupportGrand Theft Auto VI platforms, editions, and versionsRockstar GamesGrand Theft Auto VI official siteRead the full supporting guideWhat would change this answer?
An official Rockstar, Take-Two, or storefront announcement.