Upgrade 16.04.2 LTS to kernel version 4.8?

I am on Welcome to Ubuntu 16.04.2 LTS (GNU/Linux 4.4.0-62-generic i686) and when I do:

aptitude update
aptitude safe-upgrade

no upgrades are offered. aptitude search linux-headers-4.8 offers several 4.8 kernels:

p   linux-headers-4.8.0-28                                                        - Header files related to Linux kernel version 4.8.0
p   linux-headers-4.8.0-28-generic                                                - Linux kernel headers for version 4.8.0 on 32 bit x86 SMP
p   linux-headers-4.8.0-28-lowlatency                                             - Linux kernel headers for version 4.8.0 on 32 bit x86 SMP
p   linux-headers-4.8.0-30                                                        - Header files related to Linux kernel version 4.8.0

p   linux-headers-4.8.0-30-generic                                                - Linux kernel headers for version 4.8.0 on 32 bit x86 SMP
p   linux-headers-4.8.0-30-lowlatency                                             - Linux kernel headers for version 4.8.0 on 32 bit x86 SMP
p   linux-headers-4.8.0-32                                                        - Header files related to Linux kernel version 4.8.0
p   linux-headers-4.8.0-32-generic                                                - Linux kernel headers for version 4.8.0 on 32 bit x86 SMP
p   linux-headers-4.8.0-32-lowlatency                                             - Linux kernel headers for version 4.8.0 on 32 bit x86 SMP
p   linux-headers-4.8.0-34                                                        - Header files related to Linux kernel version 4.8.0
p   linux-headers-4.8.0-34-generic                                                - Linux kernel headers for version 4.8.0 on 32 bit x86 SMP
p   linux-headers-4.8.0-34-lowlatency                                             - Linux kernel headers for version 4.8.0 on 32 bit x86 SMP
p   linux-headers-4.8.0-36                                                        - Header files related to Linux kernel version 4.8.0
p   linux-headers-4.8.0-36-generic                                                - Linux kernel headers for version 4.8.0 on 32 bit x86 SMP

p   linux-headers-4.8.0-36-lowlatency                                             - Linux kernel headers for version 4.8.0 on 32 bit x86 SMP

In the German Wikipedia under ubuntu is written that the kernel 4.8 is available for 16.04.2 LTS since 17 February 2017:

The English Wikipedia and the Ubuntu release page is still on kernel version 4.4 for 16.04.2 LTS. The later one (Ubuntu release page) omits 16.04.2 LTS also and seems to be not up-to-date.

Is it a little bit too early or should I update the kernel by hand?

Ubuntu 16.04.2 installs a 4.8 kernel for new installations. For systems which are upgraded to 16.04.2 the current kernel series is maintained unchanged. If you have upgraded your system to 16.04.2 and want to have the new kernel and X server, then you must opt in by explicitly installing the hardware enablement stack:

sudo apt-get install --install-recommends xserver-xorg-hwe-16.04

This switches the kernel and X server to a rolling upgrade; see RollingLTSEnablementStack .

Also see Old kernel with Ubuntu 16.04.2 update, as user Pilot6 says.