To be realistic, this new citizenship law was initialised by the immigrants from Brazil Angola Mozambique. They often come to Portugal with tourist visas. The passport holders from Brazil do not need visa to enter the Schengen Zone. Then they submit something called “Manifestação de interesse” which shows their intention to stay in the country with their work contract signed when they visit the country as a tourist. With this kind of approach, they can change status from a short time visitor to a temporary resident. The whole process takes 2-2.5 years. It also takes them about 1.5-2 years to be scheduled by SEF for interview and biometric. Hence, they battled for their significant waiting times.
We are lucky that the brasilien immigrants are on the same side with us. The current written law does not differentiate what kind of residency can benefit. As the new updated citizenship law is currently written, I believe that it will count from the day of submitting application. Because if it counts from biometric, then the immigrants by “Manifestação de interesse” will not save a lot of waiting times (only 3-5 months max). Hence, I lean towards the date of submission.