[Question] Why do weekly notes use locale year while every other period uses year?

[TangentFoxy]

I noticed daily, monthly, quarterly, and yearly periods all use YYYY which is just called "year" in MomentJS docs, while weekly notes are using gggg which is locale year. I have been unable to find information on what this actually means, but far more confusing is why the defaults would be different for weeks vs every other period?

[TangentFoxy]

OH. It's because weeks don't evenly split between years like everything else does, so using a non-localized version would lead to the wrong year being chosen near the beginning and end of the years? And with the other periods, it would likewise choose the wrong date if the localized version were used?