TN Visa for remote jobs

My TN is up for renewal (Jan 2021), our employer drafted a letter to the POE and we kept everything ready, they will issue me the letter sometime end of Dec, 2020

They wrote in the letter saying that I am already working with them and they will require my services for another 36 months like that... they added this paragraph on the first page of the letter itself

Not sure, if this is a requirement as every time we go to Border for TN, its considered as new TN
Do you have a choice between USCIS 1-129 app and going to POE ?.


Registered Users (C)
The letter is not to establish whether you are qualified for the job -- the firm wouldn't be hiring you otherwise. The letter is to establish that the JOB qualifies for TN. The applicant (not the letter) then furnishes proof that they qualify for TN (citizenship, education, etc),