What’s actually happening here is Windows is setting its bootloader first in your EFI. Linux isn’t gone, you just have to press the “boot another drive” button and boot to it, or go into your EFI setup and switch the bootloader back to the Linux one.

Linuxes do the same thing when updating their bootloader.

Note for the Ackshually crowd: If you’re still booting MBR (which comes with the partition eating risk on dual boots) you have a system that is older than Windows 8 - 11+ years old, so eating the MBR is something you’ll have to deal with unconventionally, as all modern systems, OS, and hardware expect you to be using EFI.

Grub is still the first bootloader in that case. You would not notice if it was putting itself first after an update unless you have Windows booting first.

You might notice if you are booting between multiple linuxes, all with their own version of grub.