Luckily it's usually an easy fix if you know your way around the UEFI. Just plop grub back where it needs to be in the boot order.
Although I definitely wish Windows didn't mess with the boot order occassionally.
Also, finally, I dual-boot and I haven't actually had this happen in about a year now. I think maybe Microsoft finally stopped fucking around (with this one thing).
EDIT: Actually, it could be because I'm on Windows 10 and they stopped "Feature Updates" and all I get are security updates now. That could be why they stopped fucking with my boot order.
https://www.pcmag.com/news/microsoft-sorry-but-no-more-feature-updates-for-windows-10