Filling after sending Nonresident Treated as a Resident statement, and updating my W-4

Hi!

 

Last year, me (a non-permanent resident with work permit and SSN) and my spouse filled our tax return jointly and attached our Nonresident Treated as a Resident statement. She also applied and got her ITIN. 

 

Now I want to make sure if that status will be carried over to our 2020 return filling, so we can file electronically. Am I correct with the assumption?

 

Also, when I started with my current employer, my marital status was set to Single/Married Filling Separate, so a larger chunk of my paycheck is being withheld. Given the 6013(g) statement I submitted for last year, may I submit an updated W-4 with the marital status changed to Married Filling Jointly?