According to now-deleted listings on retailer websites, the Mass Effect trilogy remaster will launch in early March.
EA plans to finish out its FY2021 timeline with a hefty catalog boost from BioWare. Retailers may have accidentally leaked a March 12, 2021 release for the new Mass Effect Legendary Edition, which is a strategic launch for EA. The remaster should launch before the Fiscal Year 2021 timeline ends on March 31, giving EA a few weeks of sales before the period closes. Big publishers tend to release games in Feb/March to help bolster Q4 sales, which typically slumps after the Q3 holiday rush.
Neither EA nor BioWare have officially confirmed a launch date for the remaster trilogy. Right now Spring 2021 is the targeted release. The trilogy is getting big upgrades for current- and next-gen hardware, including better frame rates, boosted resolution, and lots of optimizations and tweaks. EA also confirmed the game will receive free PlayStation 5 and Xbox Series X upgrades.
Also remember that BioWare is currently developing Mass Effect 4, a sequel that has continuity with the original trilogy.