No need to rush a fix for this.
It is however recommended to adjust this during a planned maintenance window.
If it is matching the guest OS that is running then you are less likely to bump into certain support issues. The guest OS is used for a number of things by vSphere (how the virtual hardware looks like and what is installed with VMware Tools to name a few) and if it is set correctly then you are not going to waste time on troubleshooting non-issues.
Wil| Author of Vimalin. The virtual machine Backup app for VMware Desktop Products
| Vimalin : Automated backups for VMware Fusion and VMware Workstation Professional
| More info at https://www.vimalin.com
| Twitter @wilva
| VMware Wiki at http://www.vi-toolkit.com