I do think that Sigma made at that evening a clear statement. No old Sigma user will be left in the rain.
There will be no other Sigma camera anymore with SA mount. Sigma is focussing now on the L-MOUNT for every new camera they will mak.
BUT Sigma continues to develop and produce lenses for the SA mount.
I do think that this is a great message for all Sigma SA users. There is no need to switch. You can take your time and stick with the SA mount, because alle lenses will be still produced and even new developed ones will be offered with SA mount. Only if you want to have a new body/new Foveon sensor, there will be none in the future with SA mount.