The leaked boot screen picture coming from SamMobile suggests that Samsung will be skipping the S5 denomination and go straight to S6. Additional unboxing pictures show that the Galaxy Tab S6 is the first Samsung tablet to feature a rear dual-cam setup and it looks like the Stylus is getting a groove with magnetic recharger.
https://www.notebookcheck.net/Leaked-Samsung-flagship-Galaxy-Tab-S6-pictures-show-rear-dual-cam-setup.427210.0.html