Hi @Arianna_Vargas , good question! 
There seems to be an A/B test going on, as I noticed this in one of my instances yesterday.
Depending which view you are in, next to it’s name you will see an overflow menu ... where you can set it as default.
Also, once you make any changes using the Filter, Sort or Hide buttons, then a save icon with a blue dot will appear in the top right corner (where ‘save layout as default’ used to be) prompting to save the changes for everyone, or revert to the last save.
Notes:
- Changes to adjusting widths of columns, moving their positions left/right, as well as showing/hiding columns using the ‘Hide’ button is no longer live - these actions do not instantly take effect for everyone. It is now treated like a filter & sort, and needs to be saved for everyone in order to take effect the next time they visit the project (or refresh their browser).
- ‘Save layout as default’ has also been removed from the project’s action menu.