A reader recently talked to a Sigma rep who unofficially confirmed that Sigma will not produce any Sony A-mounts lenses in the future. B&H currently lists 21 Sigma lenses for Sony A-mount.
I was also told that Tamron may also stop releasing A-mount lenses unless that segment picks up (so far there is no A-mount version for the latest Tamron SP 24-70mm f/2.8 Di VC USD G2 lens). The SP 150-600mm f/5-6.3 Di USD G2 could very well be the last Tamron lens for Sony A-mount. B&H currently lists 24 Tamron lenses for Sony A-mount.
Sony announced their last A-mount camera (the 42MP Alpha a99 II) in September 2016.
