> If the laptop comes with Ubuntu pre-installed, what are the odds I can replace it with CentOS or Arch?
Very high.
For the most part, drivers on Linux are determined by the kernel version[0]. Arch typically runs a pretty new kernel, so anything that Ubuntu supports, will most likely be fine. (That applies to pretty much all desktop-oriented distros.) CentOS is server-oriented, and typically runs a pretty old kernel, and as such you need to be more conservative in the hardware you choose. That said, they do backport a fair amount of hardware support from newer kernels.
[0] The exception to this rule are closed-source drivers, but even those tend to be tied/limited to certain kernel versions.
Not to mention, that before buying my Dell XPS 15 (at the time) in order to run Debian, I mostly relied on Arch's documentation to know if it was a good purchase or not, and what wifi chipset to choose :)
The Arch linux wiki is one of the best maintained and up-to-date on hardware issues. It helps that Arch itself tries to ship only vanilla software: as few modifications as possible to the kernel, too, unlike the bigger distros.
A notable exception to this rule are Nvidia Drivers, which are close-source. When switching from the initial distribution to the newer one, you'll fall back to the free Nouveau driver and need to reinstall the NVIDIA zone by yourself.
It's not too difficult but can be surprising if you're not expecting it because your thought everything was in the kernel like I did.
Very high.
For the most part, drivers on Linux are determined by the kernel version[0]. Arch typically runs a pretty new kernel, so anything that Ubuntu supports, will most likely be fine. (That applies to pretty much all desktop-oriented distros.) CentOS is server-oriented, and typically runs a pretty old kernel, and as such you need to be more conservative in the hardware you choose. That said, they do backport a fair amount of hardware support from newer kernels.
[0] The exception to this rule are closed-source drivers, but even those tend to be tied/limited to certain kernel versions.