SonyAlphaRumors indicates that the little brother to the Sony A7R Mark IV will come out in September. For a few times in a row, Sony has followed an A7R release with a corresponding A7 release with a camera that features less resolution but some of the more recent ergonomic and other feature updates. The distance in time between the A7R IV release (about two years ago) and an upcoming A7 IV is quite a bit longer than previous generations.
The site had no details as to expected specifications.