I’ve tested out 5.0 on our dev site (unfortunately, I can’t even give you viewing access) and I come up with the same issue as 4.0.7: 2 blogs work and one doesn’t.
However, I did discover that the 4th top and bottom tool sharing option (long share bar) does work on both 4.0.7 and 5.0 on the /review blog. None of the other options will display on that blog.
The /uc and /head blogs both work fine. At least for the moment I have some sharing options for users.