AIMA announced this yesterday. Following is all I know about it. Unclear if it applies to ARI (the AIMA screenshots do show examples for “Renovação de Autorização de Residência” as well as “Manifestação de Interesse” and CPLP), or if lawyers/etc. can attend in your place.
I do hope this doesn’t result in emails like “Hey you, living thousands of miles away. Please attend this appointment we scheduled at our convenience that may be totally unworkable for you. Oh, and you probably can’t reschedule because we don’t know how to do that.” 
Original post on Facebook:
Following the analysis of grant applications or renewal of residence permit, a new in-person documentary verification may be required. If you received a call, by e-mail, with the subject “Scheduling new service for documentary verification” and according to the model presented in the images, you must attend in person at the place, day and time indicated in it.
On the day of the new service, you must take your passport and the notification received, which you must show at the entrance of the service station.
This verification is mandatory in person, scanned documents are not accepted. Failure to show up can lead to the refusal of the residence permit application.