The stable Kernel repo returns Kernel 5.3 since this morning.

Code:
rpm -qa | grep -i kernel
patterns-devel-base-devel_kernel-20170319-8.4.x86_64
kernel-firmware-amdgpu-20190827-35.1.noarch
kernel-macros-5.3.0-2.1.ga541a6c.noarch
kernel-syms-5.3.0-2.1.ga541a6c.x86_64
kernel-devel-5.3.0-2.1.ga541a6c.noarch
kernel-source-5.3.0-2.1.ga541a6c.noarch
kernel-firmware-realtek-20190827-35.1.noarch
kernel-default-5.3.0-2.1.ga541a6c.x86_64
kernel-firmware-20190827-35.1.noarch
kernel-firmware-radeon-20190827-35.1.noarch
kernel-default-devel-5.3.0-2.1.ga541a6c.x86_64
mokutil  --sb-state
SecureBoot enabled
Code:
lsb_release -a && uname -a
LSB Version:    n/a
Distributor ID: openSUSE
Description:    openSUSE Tumbleweed
Release:        20190909
Codename:       n/a
Linux localhost.localdomain 5.3.0-2.ga541a6c-default #1 SMP Mon Sep 16 06:42:44 UTC 2019 (a541a6c) x86_64 x86_64 x86_64 GNU/Linux
Kernel 5.4 on is way for Sept 29th.

All the best,