Congrats! Atleast its decision made for you. I dont even know if they will accept my case or not because similar to yours they asked for rukhsati pictures and raised questions.. they had doubts that this marriage is done only for pr.. so i sent alot of proofs .. but no response since decemberMy timeline is very similar to yours:
Feb 8th 2019 applicant
Dec 16th 2019 additional docs request (proof of rukhsati, or reason for why nikkah only application, new police certificate, couple of forms)
Jan 7th 2020 documents returned with pictures of rukhsati and new police certificate
February 28th 2020 pre-arrival
March 18th 2020 decision made on ECAS
Complete silence since then. Btw we had ordered notes sometime in early March and it showed that the officer had reviewed our additional docs just three days after we submitted them and put status as "recommended pass" on 10th Jan but we only got the prearrival end of Feb. I would recommend you order notes and see if your additional docs have been reviewed or not.