Ubuntu 18.10 is coming out on the 18th of this month.
In this new interim version, you will see kernel 4.18 and Gnome 3.30. Also the canonical team has switch the theme from ambience to Yaru with suru icons.
Kernel 4.18 introduces new hardware compatibility especially for RX Vega graphics cards.
This version of Ubuntu does not introduce any major changes. Almost sounds like a LTS version instead of an interim version.
Earlier this year Canonical founder stated that they will be more focused on security in future releases. That will explain the incremental changes.
As for the Linux gamers, I do not see any major improvements that would make me leave Ubuntu 18.04 LTS. If you need kernel 4.18, you can change the kernel in Ubuntu 18.04 to kernel 4.18 from 4.15.
However, if want to see Ubuntu 18.10. I would do it on a USB drive and not on your daily hard drive. You can also just spin it up in a VM also.