Many Linux package managers themselves tell you you should reboot your system after updates, especially if the update has touched system packages. You can definitely run into problems that will leave you scratching your head if you don't.

*nix systems are not immune to needing reboots after updates. I work as an escalation engineer for an IT support firm and our support teams that do *nix updates without reboots have DEFINATELY been the cause of some hard to find issues. We'll often review environment changes first thing during an engagement only to fix the issue to find that it was from some update change 3 months ago where the team never rebooted to validate the new config was good. Not gonna argue that in general its more stable and usually requires less reboots, but its certainly not the answer to every Windows pitfall.